Haha I'll be honest and my first thought was 'bloody hell I ask for help and he says follow these steps and share the result'. But I'm glad because I've learned something today
The filter target is +offspon.* which stops the recurring animated ads (but not the initial fixed MS Office ad which is fair enough I reckon).
By the way I also found +streamtransport.* a useful filter target for users familiar with that programme (I don't think it's in AdMuncher's default targets).