I've written the GIMP Script-Fu scripts. I've written the PowerShell wrapper. However, I can't get PowerShell to properly pass the parameters when GIMP is invoked.

The process is similar to creating any plain text file in PowerShell -- but with a few twists.

Whether the string you're looking for inside a text file is a single word or a complicated pattern, PowerShell has the ability to find and replace just about anything.