How do you save a campaign battle?

[Pinetree]

I've looked through the documentation but I can't find it anywhere. How do you save a battle from a campaign? I'm playing the first scenario in the 4/7 Dragoons campaign and it won't let me save during a turn.

I have auto save on which will save at the end of my turn but only after I've played through the AI's turn and then I'd have to play it again when I resume.

I've been forced to "Save As" the battle as a normal battle and then renaming it as the campaign.btc (Which seems to work btw).