HELP with Campaign Mod pls

[SwissSubCommander]

Hi everyone

For a while now I am tinkering on an expansion for the fantastic "Operation Monsun" mod, an Italian campaign.
I have almost everything in order except one rather important thing.
I have set my Italian Campaign to replace the 12th flottilla
in order to give it the historically accurate base at Bordeaux.
Now, since the 12th flottilla is equipped with 9D2-boats the missions set up for this flottilla are completely out of reach for the Italian sub in my mod.
They take place in the Indian Ocean and south of Africa so consequently there is also not much traffic in the mid-atlantic in this campaign.
How can I change the Missions of my campaign? Would it be possible to insert the missions of another flottilla that operates in the mid-Atlantic into my campaign?

I would really appreciate it if a more experienced modder could help me