Liz Withnell, administrative assistant to a congressman, got her friend Jan Lipkin a job on the Congressman's staff, picking Lipkin's name out of a big pile of applications, because, she says, "I knew her abilities first hand."

To help fill openings for senior-litigators at the Federal Trade Commission, its executive director, Margery Waxman Smith, calls friends such as Judith Lichtman, executive director of the Women's Legal Defense Fund, to ask, she says, "Who do you know?"

Margaret McKenna, deputy counsel to President Carter, is contacting old friends and women's groups to "get the word out" that she is looking for qualified women to fill some of the more than 140 federal judgeships which Congress may soon create.

In and around the time-honored "old boy network," which has tended to elude or exclude them, the "girls" are weaving their own web of firstname acquaintanceships, grounded in the established principle that, especially in Washington, "its not what you know; it's whom you know."

With more and more women climbing onto the upper rungs of power in government and industry, their own infant "old girl network" is hitting its stride, according to some of the "old girls" themselves.

The netsork's members are increasingly in positions to help each other out -- in filling jobs, in day-to-day problem-solving, and most important, they say, in influencing policy.

"Women's and civil rights organizations have been slow to learn in this area. I think they've always thought if you're on the side of the angels, on the side of right, then you don't have to be political, or to lobby," says White House deputy counsel McKenna, who worked in the Carter campaign as well as the women's movement.

Women in high places are more willing and able, now, to help other women up the ladder, instead of just protecting their own turf, she said.

"There are strong people here now, people who are here not because they are women, but who would have been here 10 years ago but for the fact that they are women."

Qualifications count of course, but as the Legal Defense Fund's Lichtman put it, "Sure, quality is important, but just being quality all those years didn't help us. . ."

As described by some of its chief engineers, the "old girl network" is a conglomeration of women's groups, professional groups, individual friendships, job banks and referral services, luncheons and workshops. It spans the public and private sectors and the major political parties.

In its best conception, it is more broadly based than its male dominated counterpart, they say ("not just the Harvardites and Yalees"); and does not seek to exclude men or to segregate the sexes but simply to give women the boost toward equal opportunity which they have not gotten in informal male-dominated circles.

"What's happening is that women are getting their own groups within each of the larger groups," according to Patricia Goldman, who chairs the Republican task force of the National Women's Political Caucus. "The military, organized labor, the whole downtown business scene, the stock brokerage and banking community, the various segments of government -- they each have their own separate pecking order. And now the women's groups within them are interlinking."

Goldman, noting that the president is required by statute to give a certain number of commission appointments to Republicans, said that those spots have tended to go to women. "People in White House personnel, mostly women, turned for suggestions to the only group they knew that was familiar with, and working with, Republicans (the Caucus), plus most of the pressure was coming from women. It's a bridge between the parties."

The Caucus is trading favors with a number of other groups. For instance, it is arranging a get-together for a group of female bank executives from New York City next week with speakers such as Labor Secretary Ray Marshall and other high-ranking officials, Goldman said.

"The Caucus is providing introductions to people at top levels of government so that these women can go back and say to their corporate heads, in effect, "Well, I was talking to Ray Marshall the other day . . .," she said. In turn, that group can provide the Caucus with "contacts and 'grease' for some projects we were developing."

The Caucus is also working actively to set up similar meetings for a recently formed group of women lobbyists called Women in Government Relations. The lobbyists get the government contacts the Caucus can provide, while the Caucus can use the lobbyists' connections to find good job openings and to get "seed money" for Caucus projects from the corporations the lobbyists' represent, according to members of the two organizations.

Traditionally, much of the "nitty gritty political talk" that occurs over cocktails or "at rump sessions after the main meetings" has excluded females, says Betty McCarthy, a representative for Borden Inc., and new president of Women in Government Relations, which has about 70 members. "Men appear to have difficulty including women in that kind of relationship, so we're trying to provide it for each other."

The network seems to be working best for lawyers, these days, according to several women in that profession.This is partly because lawyers are hired outside normal Civil Service channels and also because law schools are turning out women in plentiful supply, they suggested.

"In the Carter administration, when you look at where women have gotten good jobs, they usually turn out to be lawyers," Lichtman said. "They might feel that if they are going to be dealing with a woman, it's easier if she's a lawyer."

It wasn't long ago, she said, "that we didn't even know anybody to call. Now we not only know some people to call, we have a fighting chance of being listened to and getting results."

She noted that at least four or five of the major agencies now have women as their general counsels.

The effects of the women's growing influence vary. Says one of those agency general counsels, "I've offered women attorneys a great many high-level jobs, in the $40,000 to $47,000 a year range, and I was turned down by quite a few. Qualified women and blacks are in enormous demand these days in the private as well as public sector. They were able to better my offer. They'd take it and go back to their own firms and say, in effect, 'can you top this?'"

The Capitol Hill Chapter of the Caucus (with 400 members the fourth largest chapter in the country), has been fighting discrimination against women in hiring, promotions and pay levels on the Hill.

"Since we realize a lot of the discrimination is unintentional, and since there is such an informal job placement procedure here traditionally, through the 'old boy network,' we realize an 'old girl network' is one of the ways to improve things," says chairwoman Olga Grkavac. "Since the Capitol Hill employment office doesn't have an affirmative action program, we try to provide that service -- informally."

Male reactions to the "second net-work" have ranged from support to grumbling and suspicion.

"This has to be a concern," says the FTC's Smith, "but I don't think there is as much of a problem with men feeling threatened as with men using the old girl network as an excuse not to realize their own obligation to try to help women."

A number of the women cautioned against overdrawing the benefits of the network at this point.

By White House accounting, the Carter administration has put women into 155 of the 858 presidential appointee positions -- or about 18 percent.

"It's true things have improved, but the numbers are still itsy-bitsy," declared retired Air Force General Jeanne Holm, who helped set up one Republican branch of the old girl network a few years ago while a special White House assistant.

"Why, I have one whole file just on women who would be qualified for nomination to the Supreme Court, names I collected from women judges."