I do not believe it is possible at this point in time. (Note: I am just presuming.)
But, because of M3's ability to play an NDS game while "reading" a gba game (The whole, "if you have x gba game in the slot, you will get benefits in y nds game), you could theoretically be pulling AR codes from the gba "game" to the nds game. But the gba "game" would actually be a homebrew DS AR application.
Note: This is all theory, and I might not actually know what the hell I am talking about.
Edited: I edited this post so that it would make more sense. ...and to add the disclaimer that I could be completely wrong. In fact, you should wait for a real answer, and not go by anything I have said.