"Two Stones," a film about the handicapped which is to be shown at 9 tonight on WETA (Channel 26), is a noble attempt to replace the poster child concept - the leg braces under the ruffled dress - with something less attractively packaged.

But the reality represented in it is so unattractive, in ways which have nothing to do with the disabilities of the participants, that its uninflated, and therefore very small, points are nearly lost.

The film takes its names from a parable: "Two stones. One around and smooth, the other pocked and irregular. Shaped by the stonecutter, the second revealed more character by far."

The suggestion is, obviously, that the people we will see have more higly developed characters than they would if they had not suffered. That in itself is a questionable premise - why should bad luck be any more ennobling than good?

But we are then presented with four people of meager philosophical means. Two, an alcoholic and a blind amputee, work as counselors among people with similar problems, yet their advice is as inadequate as anything Lady Bountiful herself could say: "It's going to be a hard road . . . How do yo feel about this? . . . There's a need for more communication . . . Be sure and have the nurse call me if there's anything I can do for you."

The other two chief characters are a married couple, one a victim of polio and the other of cerebral palsy. The husband, at least, talks of the pleasure he has in having "someone to work for," and of the lessons he has given her in independence.

But this couple has a daughter - a pretty and healthy teen-ager - who is seen screaming "move!" at her crippled father; then she explains, in an interview, how disgusting it is to live with people who do things more slowly than she, and tells us her plans for escaping as soon as she can.

If she is supposed to illustrate the callousness of the "normal" world, then this scene is saying that the situation is hopeless, because ignorance can't be her excuse.

Perhaps the ordinariness of the disabled does need to be stressed, since being patronized is one of their problems. Occasionally, one of them is shown making the crucial point that he wants to be judged for his abilities, not his disabilities.

It would be more clearly made if they exhibited abilities.