@pone: you are right of course in repect to mp3tag that you would need a double backslash.
In WMP, though, the slash is interpreted as separator and you will get a group AC and one called DC.
So my advice would be to eliminate all slashs completely and replace them with similar looking character but one with a completely different one like ⁄ (U+2044).
Does not help a lot with the basic problem but should dampen any enthusiasm.