How do I use a period in a Quicksilver object to do things like search for a file with a period? By default pressing period anywhere in an object causes Quicksilver to switch to text mode.

Optimally I would like period to only enter text mode when its at the start of the object. Or perhaps there is a wildcard I can use (* doesn't seem to work and . obviously doesn't :). Or perhaps there is an escape sequence for period?