as oolite says, better (and easier imo) to save all of the animations in a single model file, then loop through the keyframes depending on what you are doing. just use a bunch of IF or a CASE statement to loop through the necessary frames depending on the actor's current state
i.e. if your idle animation is in frames 1 to 100 and your walking animation is in frames from 101 to 200
if actorstate = "idle" then loop object actor,1,100
if actorstate = "walkfwd" then loop object actor,101,200
etc etc etc for all of your different animations
This is not the Sig you are looking for....