Try to search forums better cause custom animation was already discussed 4 example here:
http://forum.thegamecreators.com/?m=forum_view&t=69554&b=24
BTW, i also met such kind of animation trouble (for now i'm makin a flying helicopter model), and i solved it as
;anim debug
:state=0,animate=1
:state=1,animate=1
........etc.......
:state=X,animate=Y
inserting this inside the script will tell your model to animate without any conditions except the STATE value
dont forget to remove other "animate" expressions in script
Enjoy
never say never