I'm not familiar with trigger groups, but you can use the comma trick to act on more than one thing at once.
For instance:
1. Bring up Quicksilver
2. Search for Mail
3. Hit the , key
4. Search for Safari
5. Hit ↩ to launch them both (assuming “Open” is the default action for applications)
You should be able to define a trigger that does this.
--
Rob McBroom
<http://www.skurfer.com/>