IT IS HARD TO THINK of a worse running together of missions - one valid and the other grotesque - than that reflected in the new Civil Rights Commission report on women and minorities in television. Acting within the realm of its mandate, the commission addressed its attention to hiring and promotion practices within the television industry. Fair enough - had it only stopped there. But the commission went off the 32-foot board into another subject. It doesn't like the way society is being portrayed in some of those TV "sitcoms" you have been ingesting along with your pretzels after a hard day's work. And it wants the FCC to do something about them. If there weren't more than four months to go in 1977, with all the rich possibility that suggests, we would award this the prize - hands down - for the worst idea of the year.

Making use of some studies that others have made and its own notions about what is socially constructive for us to view - e.g., how Mary Tyler Moore should have behaved in relation to Mr. Grant, and Edith Bunker in relation to Archie - the commission suggests two basic goals for TV drama programming. Neither is very good. And they are, in addition, contradictory. One is that there is some kind of palpable, statistical reality among us that it is the duty of the tube to "represent." For instance, citing a study: "The major departure from reality on the age dimension . . . occurred in the portrayal of females. As noted above, nearly half of the nonwhite female characters were coded in the 21- to 30-year-old group. Although the difference between fact and fiction is not as great for white women, 21- to 30-year-old white female characters were also overrepresented on the television screen."

Is it accurate to say, then, that the Civil Rights Commission would like the TV dramatists faithfully, even slavishly to "represent" what the statistics tell us we are as a group? Well, not exactly. We can think of several statistical realities it clearly would just as leave not have depicted at all, because, you see, the second part of its charge to the programmers is to provide a little inspiration, a little uplift for minorities and women, a little agitprop you might say. The commission believes it is a damned shame that so much housewifely contentment is shown in these TV dramas and that there just aren't enough minority and female characters shown running the world to represent . . . what?Well, not reality, but the commission's idea of what the reality ought to be.

Now, this sort of thing might go down all right in Bulgaria - and, in fact, does - but it is a preposterous suggestion to make in a country that deals in commissions, not commissars. Poor old Othello and Emma Bovary, what chance would they have under the Civil Rights Commission's guidance? Or, to get more homegrown about it, what is to be done with Huck Finn's deferential black companion, Jim, or - God have mercy on the soul of a fallen woman - Hester Prynne? Will Hester in fact have to win her scarlet letter henceforth as a quarterback for the University of Alabama?

We will be plain about it: We're no crazier about racial, ethnic and sexual stereotypes than the commission is. And we think it is in fact a healthy note in a free and robust and hopelessly argumentative society such as this one, that within the political arena pressures are brought by various groups to assert their cultural claims. But there is surely no place for government meddling of this kind in the scriptwriting business or in the editing of television drama. Government's would be the dead hand. And if you have any doubt about that, just read the Civil Rights Commission report.