Text editor suggestion?

[Rantz]

I don't think any editor will make that super duper easy. If you do stuff like that often I recommend learning basic regular expressions and using a tool like SciTE or Notepad++.

Edit: Actually, it's pretty easy to record a macro in Notepad++ and running a loop on that macro which will do the job.

Editga: Apparently Notepad++ also has a "column editor" which lets you insert text into all rows on a given column. That makes prepending super duper easy, but it pads the shorter lines if you try to append. There's probably a way around that.