Use the export feature in PAC Control (right click the I/O Units folder). Save the file, then open it with excel (it is comma separated). You should then be able to sort and move things around in Excel to get the IO unit names together.
You can then copy those names into a new sheet and write a formula to generate the OptoScript you need to assign to a pointer table and then copy this back into your strategy if you are familiar with Excel formulas.