We have one proxy set up so that external users can hit the external
address of our BM server to get to an internal server via SSH.

The proxy is 66.X.X.X:22 (External) and (Internal)

Now, we have another internal server we'd like to provide SSH access to
but when I set another generic proxy this way:

66.X.X.X:12022 (External) and (Internal) and it doesn't

Since I know squat about SSH is it because SSH *has* to use 22 as the
port? If so, is there any workaround? Thanks!