I don’t use Soundcloud so I can’t test it myself. But you could try this:
When Podlove is looking for a media file, it checks the files at whatever Upload Location is set in Podlove -> Podcast Settings -> Media. This can be on other servers. (It could even be a good idea to host your files somewhere else.) Therefore you could insert the Soundcloud upload location there - if Soundcloud even tells you where this is.
Maybe we are talking about the same field:
As far as I understand it, Podlove usually creates its own RSS-Feeds. It does not “enhance” an existing one.