that would only be a problem if you held the upkey down (as you would if you where moving the object), what you need to do is to start the object playing and then leave it alone, if you keep asking it to play then it will be stuck right at the start of the animation, try this
do
if upkey()=1 and playing=0
play object 3,0,23
playing=1
endif
loop
that will start the animation playing and then leave it playing for as long as the flag "playing" is equal to 1, when you want to end the animation playing and leave it available to play again then set "playing" to zero and stop the animation, I think this is what you meant anyway, post again if it isn`t.