Search query

I have two questions about search queries, e.g., used for smart groups.

  1. How do I search for a specific type as it is displayed in the type column? For instance, I want to find all ppt files. The popup list shows some predefined types I can search for, but I cannot write arbitrary ones.

  2. I can search for file names that contain a certain substring. However, how can I specify that I am looking for file names that start (or end) with specific characters?

Here are my settings:
DEVONthink 2.0.6 on Mac OS 10.6 (German localization in case this is relevant)