Hi all, I've read the manual on this and I can't figure it out. I was wondering how you set a character in combat to use the crossbow by default (ie auto combat etc).

Are you sure it's even possible? I didn't read the manual (I had it first way back when the floppy version, w/o the manual, was freeware, and I pretty much remembered how to play it even now), so I don't know what it says on the matter, but I personally don't remember any way to do so.
I've read some places (for example, here, in the "tips" section) that auto-combat is a not-so-decent feature of BaKr; maybe that's partly because you can't tell your characters what to do?