You can do this using a Modify Format/Case preset. You just configure what text to add as a prefix, then optionally set a hotkey to make it really easy to apply, then save it.
Then just select your text in any program, and trigger the Formatting Preset (either via hotkey or via the quick paste menu under T-Formatting Presets); it will copy the text selected by you, then modify it, then repaste it back in.
I'll try to make a video tutorial next week if this isn't enough info -- I'm just really busy next couple of days on the DC fundraiser preparations.