Ok just checked out the Ipac.

This is simple really. No need to to mess with Client software or re-programming the I-pac.

Lets pick for instance Cycle start. Choose the input your going to use on the I-pac and fit a button, lets say "start 1" then get the Key code it use's which in this case is "1"

Now this this the bit where you need Mach screen designer found here Hard - und Software

This software is good but has it's little quirks so you'll need to get used to how it works so I suggest you make a copy of any screen sets your working on and for good measure I'd also backup your XML file.

What you do is easy. Load the screen set your using. Select the screen button your emulating and now in the box that appears select image button from list, now in the floating properties menu window you'll see all the options for that button. There you'll see Hot key so click in it and type the i-pac code for the input your using.

It's that simple. Oh remember to push enter after changing code and then obviosly save before closing. . Lol.