I've found that it's easy to add a recently opened document with help of SHAddToRecentDocs
Windows 7 Jump Lists somehow do it by knowing only program shortcut. Programs added to Windows 7 start menu also allow to access their corresponding recently opened list.
A .NET wrapper for Windows API is prefered but anything will do :)
It looks like you can get them using the IApplicationDocumentLists interface. However that looks like it gets the list for the running application, not for an arbitrary application. I'm trying to find the recent docs for any application based on their shortcut. It sounds like that's what you were trying to do also? You still never found a solution?