How can I press the # key in a DOSBox game?

I don't think it's possible to map a key specifically to # instead of to 3 in DOSBox. I tried using the built in keymapper and manually editing the .map file, and neither one had that option. I then tried adding the lines key_# "key 97" and then key_pound "key 97" and deleting the binding for the A key, and that didn't work either. (I was using the A key for testing) Your only other option would seem to be editing the source and compiling your own copy of DOSBox. Whether or not go to that length is up to you.

After refreshing my memory with the manual, the game is not expecting you to press the # key. It is expecting you to press a number that relates to the town you want to go to.

1 = Inn of Sorpigal
2 = Inn of Portsmith
3 = Inn of Algary
4 = Inn of Dusk
5 = Inn of Erliquin

To start the game, press 1, select all the characters (CTRL+A, CTRL+B, ..., CTRL+F) and then press X to exit the Inn.

I had a similar issue for M.A.X. (Mechanized assault & exploration), and found a pretty weird workaround for typing keys using alt-gr under Dosbox, in-game.

Press & hold ctrl
Press & hold alt-GR
Press & RELEASE target key (e.g. "3" for # or "8" for "[", on french keyboard)
Release ctrl
Press as many target keys (ones using alt-GR) as you need  (works normally)
And at last only, release alt-gr.

I'm not certain it works the same for M&M as for MAX, but my post isn't intended for the OP anyway, since his (old problem) seems solved already.

Finding infos about this kind of specific issues is quite a hassle, so I don't want it lost... and guess I might not be the only one ending-up here looking for that. Tested on Dosbox 0.72 and 0.74-3