I don't have an Hd5 and I hate Real Player as well as Sonic Stage, so you'll have to take this with a grain of salt.

I know that Sonic Stage can wrap MP3s so they can play on the player. It may be able to convert WMAs to its own format (AAC?), or if not, you can convert the WMAs to MP3 format and then let Sonic Stage wrap them. But I really doubt it can handle DRM WMAs or DRM Real format. If that's what you have with Real, you're probably out of luck.