So I thought the only way to convert a MP scenario to Campaign was with a HEX editor but Sapien can do it. Open the scenario then select the root folder, in the other panel you should see a drop-down list set to Multiplayer. When you select it the other options will be blanked out but they will still work, you just need to know the order, I used Entity to find which is which:

00: Single Player
01: Multiplayer
02: Main Menu
03: Shared
04: Single Player Shared