Ronald Reagan weighed in with his first presidential statement on Puerto Rico the other day. Regrettably. Puerto Rico has become something to toy with in mainland politics, and he toyed with it. It has to be recognized, however, that the island asked for it. Though Puerto Ricans don't vote in presidential elections, they do take part in the nominating process. By playing the Hispanic card and, in particular, by scheduling their conventions early, when the candidates seek momentum, they assure a certain kind of attention to their affairs.

It's the wrong kind. Poverty and development is a legitimate issue on the island, but it gets scant play from mainland politicans: it's too hard. Reagan gave it short shrift in his statement Tuesday.

He gravitated to the no-easier but more crowd-pleasing issue of political status: should Puerto Rico remain a commonwealth or seek statehood or independence? This is in a by-now- familiar presidential pattern. In this instance, leading island Republicans solicited a statement from the president. Democrats jumped aboard.

Reagan, an old statehood supporter, believes statehood would benefit Puerto Ricans and demonstrate to a strategically significant Caribbean gallery the spaciousness of the American spirit and the effectiveness of the American way. He underlined this Tuesday and added a twist: a pledge that if Puerto Rico becomes a state its Spanish language and culture "would be respected."

So what's wrong with saying some friendly words to a group of worthy, put-upon American citizens?

By espousing statehood rather than the neutral self-determination, Reagan intervenes without warrant into the broader choice: statehood, commonwealth or independence.

He inserts himself, moreover, at a moment when Puerto Ricans are dismally and divisively stalemated between trying to improve commonwealth and seeking statehood; independence has no political base.

Nor can he ensure that, with statehood, Puerto Rico's Spanish heritage "would be respected." That and the island's poverty and its ambivalence on status would unquestionably make Congress hesitate to grant statehood, even if the Puerto Ricans could get themselves together and ask.

All this is why it is toying with Puerto Rico to join its status debate casually. No end to the island's paralysis is in sight. Some Puerto Ricans, overcoming their usual resentment of U.S. highhandedness, would like Washington to butt in and somehow make them make up their minds. But this is inconsistent with Puerto Rico's prerogative of self-determination. The mechanics are unpredictable.

I am fully prepared to make the acknowledgement that many intense Puerto Ricans are eager to have mainlanders make: the island is a colony, though a pro-American one, a colony by consent. Puerto Ricans are second- class citizens. But how to unscramble this 84-year-old omelet, pulled one way by dependency, another by pride?

In the inability of the Puerto Rican political culture so far to solve this riddle lies the need, I think, to focus on improving commonwealth, which exists.

What that means is clear. It means consulting Puerto Rico more closely in the fashioning of policies affecting its interests. Since the island lacks the usual levers (a presidential vote, voting representatives in Congress) to influence the federal establishment, that establishment has a special obligation to ease the sense of Puerto Ricans that they have no control over their destiny.

Here Reagan has treated Puerto Rico shabbily. It is not so much that he has made big welfare cuts and, in his broader Caribbean approach, tended to neglect the island. It is that he has pretty much thrust these changes on Puerto Rico, with no real consultation.

Still, many Puerto Ricans are strangely forgiving. So intense is their frustration over the status stalemate, they seem to care more for Reagan's encouragement on statehood--as misleading as it is, or so I would argue-- than they complain about his budget cuts and neglect. If this is their choice, then perhaps the president can't be faulted for going along.