Finde associeret program ud fra extension:

Jeg fandt selv løsningen efter et par dages arbejde:

API'en SHGetFileInfo klarer problemet:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/shellcc/platform/shell/reference/functions/shgetfileinfo.asp

Klip fra siden:

If the uFlags parameter includes the SHGFI_USEFILEATTRIBUTES flag, this parameter does not have to be a valid file name. The function will proceed as if the file exists with the specified name and with the file attributes passed in the dwFileAttributes parameter. This allows you to obtain information about a file type by passing just the extension for pszPath and passing FILE_ATTRIBUTE_NORMAL in dwFileAttributes.

This string can use either short (the 8.3 form) or long file names.

/tjacob