Inserting a track into Audition multitrack - how?

This has got to be simple but as a video editor, simple is was I need.

All I want to do is insert 12 seconds of an audio clip into an existing Audition CS5.5 multitrack session and shuffle all the other clips on all the other tracks down the timeline and I can't find out how to do it.

Inserting silence works but I want to do it with a clip. When I paste it just overwrites (video edit term) - I can't insert. Lot of web and soul searching has not revealed an answer - so how is it done? I suspect a wicked combination of alt/gr, apple key, shift and backslash is involved!


Many thanks.