I was unable to access the console (perhaps because I use a Japanese keyboard).
If you're unable to access the console, you can add the [seta in_mouse "-1"] (without brackets) directly into the game configuration.
Go to the c drive for the bottle where you've installed MoHAA. Go to:
Program File/EA GAMES/MOHAA/Main/configs
and open unnamedsolder.cfg with textedit.
Add [seta in_mouse "-1"] (again, without brackets) to the end of the list, right after the other seta commands. At the end of the list you'll see
//
//Aliases
//
I put it right before that. Like this:
seta in_mouse "-1"
//
//Aliases
//
That solved the mouse problem for me.
