I have a problem with “few” computers with windows 8.1.

I have a PowerShell script that I am working on and I am trying to figure out how to have it catch the non-terminating error and return a custom error message instead of the standard error message text. I am specifically concerned with 2 different errors that I expect to see based on parameters and how I can have the script return a custom error text depending on which error it is instead of returning the long system error.