resource icon

I am importing 11k files into XFRM. Most of these are documents like PDF and DOC. I would like to add an icon to these files according to the file type. So that PDF's get a PDF icon, DOC files get a DOC icon, etc. Is there a way to do this? Maybe with a query?

The default resource icon can be a ".png" while the custom uploaded icons are automatically converted to JPG with the name then being "*.jpg.png" which seems odd to me. Is this bug? It would be great to have PNGs with their alpha channel appreciated especially since the resource icon is being...