I have a need to create a wrapper for a DLL, loading and unloading it as needed (for those interested in the background of this question, see How to work around memory-leaki
Do you need to call COM methods on this DLL? If so, I'm not at all sure this is possible.
Matthew Curland's excellent Advanced Visual Basic 6 is the first place I'd look, though. There's some powerful under-the-hood COM stuff in there that circumvents the normal VB6 techniques.
There's also DirectCom, which allows you to call COM methods without using COM. Never used it myself, but people chat about it on the VB6 newsgroup.