You can use CC Link - set up a device to represent your computer or MIDI controller if you don't already have one. Then, turn on CC Link on any IA button that you want to control. Add a CC Toggle action to the button. It needs to be the first action on the button. Set Device to your computer, then set the CC number.
When the computer sends that CC number on the computer's channel specified in the Devices tab, it will control that button.
For example, you have this device entry:
Device 3: PC
MIDI Channel: 5
Port: USB
And an IA button with CC Link turned on and this action on it:
CC Toggle #23 off:0 on:127
When the computer sends CC#23 with value 0 on channel 5, the button will turn off, and if it sends CC#23 with value 127 on channel 5, it will turn on.