Can you dynamically assign CFBundleDocumentTypes to your Cocoa application?

Question

Can you dynamically assign CFBundleDocumentTypes to your Cocoa application? Meaning during run time can I assign more extensions for my app to handle.

Currently I set some extensions for my app to handle using CFBundleDocumentTypes in the Info.plist, but I would like to do this through code while the application is executing (during run time). Basically can I make Launch Services aware of new extensions without modifying the Info.plist file.

Thanks.