(MONEY Magazine) – After last year's 30% gain in Standard & Poor's 500-stock index, there aren't many bargain stocks out there. One way to find the hidden gems is by using a computer and the right investment software or on-line data-base service. But which are the best among the hundreds on the market? To find out, MONEYconsulted John Bajkowski, associate editor of the book Computerized Investing ($24.95; American Association of Individual Investors, 625 N. Michigan Ave., Chicago, Ill. 60611). He came up with four recommendations. All offer fundamental analysis, which looks at the financial underpinnings of companies, as opposed to simply technical analysis, which studies trading volume and stock-price movements. Using the technique of screening, you enter one or more criteria -- for example, a price/earnings ratio below 10 -- and the computer spits out the names of stocks that pass your test. Of Bajkowski's picks, two are programs with diskettes that are updated regularly and mailed to subscribers. The PC Stock Market Databank ($55 a year; American Investors Alliance; 305-561-1900), which runs on IBM PCs and clones with at least 640K memory, lets you screen 4,600 companies. This software also lets you see the vital statistics for six firms at the same time, a useful feature for comparing stocks, say, within one industry. The respected Value Line organization offers Value/Screen II ($49 for a trial subscription, then $295 a year; 800-654-0508), which runs on any IBM or clone with a minimum of 512K memory or on any Apple Macintosh. This software provides data on 1,600 companies. Its most useful feature: Value Line's famed stock-ranking system, which classifies equities based on their earnings growth record and safety.

The other two electronic aids are features of the popular data-base services Prodigy and CompuServe, which you hook up to through your computer's modem and your phone line. Both provide not only stock screening but also news, weather, travel and shopping information. Prodigy's Strategic Investor ($27.90 a month, including the cost for Prodigy's basic service; 800-776-3449), which can be used with IBMs or clones with at least 512K memory or with any Macintosh, offers key financial data including current prices for 4,500 stocks. CompuServe's more sophisticated service ($12.80 per hour of use; 800-848-8199), which can be tapped into with any computer, is stuffed with figures on 10,000 companies. Count on spending $35 to $60 a month to do five screens.