Use "System Compare Two Values" condition. left(Character.AnimationName,4)="Anim"
Be aware, that this condition doesn't pick instances, if you have many character instances, then use "System Pick By Evaluate" instead.
If there are many "AnimN" animations and you want to check if only animation 1, 2 or 3 is playing, then you can use this expression:
left(Character.AnimationName,4)="Anim" & int(mid(Character.AnimationName,4,1))<4