The Dink Network

Ok, so I wanna create a cutscene where a sprite is talking, then I want to make that sprite larger, not to become larger immediately, but rather grow slowly to a bigger size (and shrinks later in the same manner). Kinda like:
...
say("random cutscene crap talk thought up by the author",&currentsprite);
wait(time needed to enlarge the sprite);
//enlarge the talking sprite command here
say("another random cutscene crap talk thought up by the author",&currentsprite);
wait(time needed to shrink the sprite);
//shrink the talking sprite command here
say("meow",&currentsprite);
...

Is there such a command? I'm sure I've seen it somewhere.