Well I don't really understand what you're trying to do but let me rephrase how the downloading occurs:
- client connects, client receives the list of required/precached files
- client receives the download URL (if defined in sv_downloadurl)
- client attempts to connect to that URL and attempts to download the files from the list
- if any files weren't on the URL, the client will download them from the server
That's all I can help you with right now since, as I said, I don't really understand what you're trying to do.