Help, How to Connect 4 pads to 1 PC?

Please help.
Sorry for my English.
I need to connect 4 pads USB to one computer and 4 person can play one time.

I asked in shops, sellers said that I need special version of stepmania for 4 pads.
I tried to find information, but I found only 2 tabs connection possibility.

Is it possible?
If yes, how to make it?

An unofficial 4-player version of StepMania 3.9 can be downloaded here. This version is definitely unsupported by anyone except cspotcode, and probably unsupported by him as well.

An unofficial 4-player version of StepMania 3.9 can be downloaded here. This version is unsupported by anyone except cspotcode, and probably unsupported by him as well.

Thank you very much for help. I'll try to run it.