Qprocess question

[Spitfire]

You're trying to open txt file, no wonder it doesn't do what you want

This is what you want:

QProcess* prc = new QProcess(this);
    prc->start( "C:\\Windows\\system32\\notepad.exe" );

QProcess* prc = new QProcess(this);
    prc->start( "C:\\Windows\\system32\\notepad.exe" );

To copy to clipboard, switch view to plain text mode 

As to linking button from your app to button inside Blender app, AFAIK it's impossible.

ps. use [code] tags.