If the name on the other medium is already taken, you're SOL. If not, you can try to address the respective support group and ask whether they can change your name. In my experience, they're a friendly bunch and if it's possible (and you keep it polite), they'll fulfil your wish.
It would be a good idea, though, to check beforehand whether the name is actually taken - both ED and the forum have options to search for or contact a participant whose name is known. And if Glamis is already taken on the forums, CMDRGlamis might be an option (and about equally confusing to having a CMDR Thane / Glamis and probably a CMDR Glamis / Thane...).
Edit: Ninja'ed by a mod...