I use a UX-1 with Realband and here's what I do:

Mine is always on and I can use the Output dial to control my computer speaker volume along with my computer's speaker volume knob.
With the computer,s speaker knob off the UX-1 Output can control your Headphone volume for playing without "entertaining" others.

To use with Realband:
Open "Gearbox" program that came with your UX-1 (or install it if you didn't yet)

Once in Gearbox go to "Source Select" and using the drop down menu, select your input, either Mic or Instument.
You can only do one or the other with the UX-1.

Gearbox also has tons of modeling effects if you want to use them though most add the effects to a dry signal after recording into Realband.

If you are using a powered condenser mic remember to plug the powered mic signal cable into the UX-1 mic slot.
Dynamic mics of course can plug into that slot and the UX-1 acts as your pre amp.
Remember to turn your Mic Gain knob up.

I always use the red Record Audio button in Realband (has the white sound wave on it) since it will automatically change you track to audio if by chance it was set to midi.

Hope this helps,
Carkins