First of all, make sure your joystick works.
Run "joy.cpl" from the command prompt, or the start/run menu(You are using microsoft windows, right?) If all your buttons and axes are recognized from that program, you can use the Standoff, or even SO to give you "basic controls". If the controls do not respond to joy.cpl, there is no way to use them to full functionality in standoff..
You are using Xpadder, so I asume you are using a gamepad from a a playstation3 or xbox360? I prefer to use joy2key, or ppjoy myself. Also, Windows has native support for the xbox360 controller.