Just for info:
you don't need to export your mission to multiplayer,
to be able to play it and maybe change it.
In multiplayer, where you can select the maps, there's also
a mission editor.
If you use this one, and you save your mission (not export
to sp or mp), you will find your mission in:
c:\program files\codemaster\operationflashpoint\users\your_name\mpmissions
You can start a multiplayer game aswell from such an open
source mission (not yet exported to sp/mp).
:note - in case you're using custom music, remember
that everytime you change anything on the map, the connected
clients will have to download the mission again.
:edit - ah yeah - almost forgot: could be, you posted into the
wrong forum (multiplayer editing would be the right one)
~S~ CD