Microsoft brings a fresh breeze of legacy Mac OS 9 power to the year 
2004 and beyond by using HFS resource forks to store their bundle 
identifier - which breaks everything modern like NSBundle (which is 
used by Remote Buddy for this) - entitling their users to enjoy a 
wealth of compatibility issues they would never ever have dreamed of 
before .. ;-)

But, of course, there is a way to do what you want:

1) Manually create a new behaviour by pressing "+" 
2) Enter "com.microsoft.PowerPoint" in the "Bundle identifier" field 
3) Enter "PowerPoint" in the "Name" field 
4) customize the Identifier field in the "Behaviour bundle metadata" 
field to something like "com.mathew.scriptedbehaviours.powerpoint"

Preview 7 will cope with Microsoft weirdness, though. ;-)

However, unless you want to entirely rebuild a PowerPoint behaviour 
from scratch, you don't need to create a Behaviour in the Behaviour 
factory. Creating the respective actions in the "Action factory", 
that is

1) Creating them with "+" 
2) Name them for clarity 
3) Add a keystroke actor for B and W 
4) Activate the "Action globally available" checkbox

and then simply choosing them in the PowerPoint behaviour's mapping 
overview is probably what you want.

Cheers, 
Felix