Now my Qustion does basswma searching self if the bass.dll is present in the Searchpath or does basswma looking if the bass.dll is in the memory ??
The add-ons are linked with BASS.DLL, so it needs to be either on disk or already loaded in memory. Note by "loaded in memory" I mean that Windows loaded it, not just somewhere in memory
basswma.dll does not scan the memory for a loaded instance of BASS.DLL. It just does a LoadLibrary("bass.dll") call relying on Windows search path.
Not that it makes much difference, but BASSWMA doesn't actually use LoadLibrary (it used to in the old days to allow multiple instances/devices). It's linked with BASS.DLL now, so there's no need.