I have a weird question...

I have an analog line (in CO port 1) that functions as so,

Dialing the number rings out on 1(111)111-1111
Dialing #1, then the number calls out on 1(111)111-1111
Dialing #2, then the number calls out on 2(222)222-2222

What would be the simplest way to allow a user to select either number to call out on?