Michael,
I have been using MediaShout since 2.5 and never know this combination existed. so I asked around to those who have been here just as long and they too were not aware of this combination. So I opened V4 and tested it. Unfortunately, I could not reproduce it. The only combination that works with the CTRL button for copying is CTRL+C.If it did work in V4 like you say, (although cool) it was not intentional and will not be added as a feature.