In case you don't know yet, the standard operation is to add an empty file titles ".nomedia" to any folder you don't want to be scanned for media. This works with most mustic players I've tried, including Google/Play Music.
In Windows, you can't name a file with just an extension but you can with cmd prompt. So just create a text file with right-click->New->Text file called "nomedia.txt" and use cmd prompt to do "ren nomedia.txt .nomedia"
then copy that folder to your ringtone folders, regardless of name.