WHO WILL help you if you're not lucky enough to catch the president's eye? Suppose you've been out of a job for months and your family is about to be evicted. Or you've been wandering the streets ever since the mental institution that used to be your home decided you were cured. Where can you turn?

Some people in trouble do get lucky--if that's the proper word for it. Some show up in a public shelter with photogenic children who attract the media's attention. That will bring an outpouring of clothes and food and even job offers. Some, like Reginald Andrews of New York City, come to national fame. Mr. Andrews, the father of eight children, has been unemployed for a year. Last Monday, while returning from applying for a job as a meatpacker, he saved a blind man who had stumbled between two cars of a subway train. His heroism earned him a job offer from the meatpacking plant.

Mr. Andrews also received a telephone call from President Reagan, who is frequently moved to such action when individual acts of heroism or hardship are brought to his notice. No president, however, can talk with each of the 12 million jobless or the more than 30 million people living in or near poverty, much less deal with their problems on an individual basis. They need more tangible kinds of help.

For most of the unemployed, the first source of help is unemployment benefits--now running at an annual rate of more than $30 billion. But unemployment benefits are usually low relative to prior earnings, and they run out -- less than half of the unemployed now qualify. The next recourse is help from friends, relatives or union organizations. But in many areas where the plants or mines that were the primary source of jobs have shut down, more than half of the labor force is unemployed, and few people can afford to provide steady help to their neighbors.

Public welfare is one possible resort -- if you're willing to sell off most of your assets or let the government put a lien on your home. And even then, in many jurisdictions you can't qualify for anything but food stamps if you don't have young children or if there is an able-bodied man in the house. As the unmet needs grow -- and as the federal aid that sustained many nonprofit community services shrinks -- charitable organizations are stretching their already strained resources to fill the gap. Congress wanted to provide an extra $50 million to help these organizations, but dropped it from the omnibus appropriation passed this week for fear of a presidential veto.

There are other limits to relying on voluntary charity. Most Americans are glad to donate food or clothes or money, or to organize charity drives and benefits. But many of the down-and-out aren't very appealing people up close. It's hard to persuade middle-class people to drive each day to where the poor are, to work in soup kitchens and shelters, to quiet the deranged, sober up the drunk and find jobs for the desperate. Most of the burden of hands- on private charity tends to fall on the people who should find it hardest to bear -- the residents, churches and other institutions of the inner city who, to their great credit, share their scant resources with those still less fortunate.

There is something to be said for symbolic gestures as an instrument of leadership. But Mr. Reagan's gestures really have no particular beneficial impact. They concentrate the public attention on what a nice fellow he is when confronted by the specific suffering of another. But they do not show the way to any kind of relief for those who are victims of economic and social forces beyond their control -- circumstances for which Mr. Reagan himself bears some degree of responsibility.

How much more moving it would be to know that he was inspired to take action to alleviate the distress of people newly brought to hard times than to know that he has telephoned to encourage one of them. Mr. Reagan wants people to know he cares. People want to know that he cares enough to do something about it. For that we all still wait.