The national commander of the Veterans of Foreign Wars has asked the group to approve a nationwide campaign to raise money for the U.S.-backed guerrillas who are fighting to overthrow the leftist Sandinista government of Nicaragua.

VFW National Commander Bob Currieo, who has talked up the project with local VFW commanders, said he expects "strong support" when it comes to a vote at the group's national convention in New Orleans this month. He noted that the organization's bylaws require it to oppose communism in Latin and Central America.

Federal law does not prohibit a private group from offering nonmilitary aid to foreign groups that are not acting against the national security interests of the United States, according to congressional legal counsel.

With 1.9 million members, the VFW is the second-largest veterans' organization; the American Legion has 2.7 million members.

Currieo spent eight days traveling through Honduras, El Salvador and Costa Rica last month, and then briefed President Reagan on his trip for a half hour in the Oval Office July 27. He said he was not seeking to circumvent a recent House vote to stop steadily increasing CIA support of the anti-Sandinista guerrillas, called "Contras."

"I met with the Contras while I was in Honduras and Costa Rica, and these are freedom-loving people trying to retake control of their country Nicaragua from dictators and bring about a democratic society," said Currieo. "They consider their country to be under the influence of a superpower, the Soviet Union, and they are asking only for help to keep the Soviet Union out."

No amount has been set for the VFW contribution to the guerrillas, but Currieo predicted that several million dollars can be raised for food, clothing and medical supplies. He said the money would be channeled through a nonprofit, Washington-based anti-communist group called the American Security Council and would allow the "Contras" to spend their funds on military hardware.

The vote on the resolution for the fund drive will come after Reagan addresses the convention. Sen. John Glenn (D-Ohio), a candidate for the Democratic presidential nomination, is scheduled to speak immediately after Reagan. But Currieo said he didn't expect either to take a stand on the resolution. He said he had not discussed it with Reagan, although White House aides are aware of it.

"We are doing this without consulting with the president," he said. "But I am behind his policies in that area 100 percent. I told the president there is no question in my mind that our effort down there is right and we should feel obligated to help those people."

In addition to addressing the VFW and several Hispanic groups during his three-week vacation on the West Coast, Reagan is scheduled to speak to the American Legion's annual convention.

"We are very supportive of the president's Central American policies," said Mylio Kraja, executive director of the American Legion. Kraja said the American Legion has no plans to funnel aid to Latin America independently.

Its own charter prevents the other major veterans' group, the Disabled American Veterans, from taking a position on American military action in Latin America, but its members are supportive of Reagan's policies.

Reagan will face a challenge in winning the support of Vietnam-era veterans, who have made recent gains in the groups' hierarchies. Those men, according to officials of both groups as well as Reagan's political advisers, are less amenable to the idea of possible military intervention.