QUOTE(martynonline @ Mar 10 2008, 19:28)

I cant do this using the commandline as i especially need it for when i run mp3 files from windows.
Well, you can, but you'll need to edit the Windows registry for that. You can save the following to a .reg file and double-click it to import it (it works on Windows XP at least):
CODE
Windows Registry Editor Version 5.00
[HKEY_CLASSES_ROOT\foobar2000.mp3]
@="Audio file (MP3)"
[HKEY_CLASSES_ROOT\foobar2000.mp3\DefaultIcon]
@="C:\\Programme\\foobar2000\\icons\\mp3.ico"
[HKEY_CLASSES_ROOT\foobar2000.mp3\shell]
@="play"
[HKEY_CLASSES_ROOT\foobar2000.mp3\shell\enqueue]
@="Enqueue in foobar2000"
[HKEY_CLASSES_ROOT\foobar2000.mp3\shell\enqueue\command]
@="\"C:\\Programme\\foobar2000\\foobar2000.exe\" /command:Default /add \"%1\""
[HKEY_CLASSES_ROOT\foobar2000.mp3\shell\open]
@="Open in foobar2000"
[HKEY_CLASSES_ROOT\foobar2000.mp3\shell\open\command]
@="\"C:\\Programme\\foobar2000\\foobar2000.exe\" /command:Default \"%1\""
[HKEY_CLASSES_ROOT\foobar2000.mp3\shell\play]
@="Play in foobar2000"
[HKEY_CLASSES_ROOT\foobar2000.mp3\shell\play\command]
@="\"C:\\Programme\\foobar2000\\foobar2000.exe\" /command:Default \"%1\""
The changes from this will be lost when you modify file association settings in foobar2000, and you will have to reapply them.