win32com: how to connect to a specific instance of a running object?

[ago]

The other approach I tried (as suggested by Tim, thanks) involves
browsing the ROT.

import pythoncom
SPREADSHEET_NAME = r'\MySpreadsheet.xls'
lenstr = len(SPREADSHEET_NAME)
obj = None
rot = pythoncom.GetRunningObjectTable()
rotenum = rot.EnumRunning()
while True:
	monikers = rotenum.Next()
	if not monikers: break
	ctx = pythoncom.CreateBindCtx(0)
	name = monikers[0].GetDisplayName(ctx, None);
	if name[-lenstr:] == SPREADSHEET_NAME:
		obj = rot.GetObject(monikers[0])
		break

The obj I get is a PyIUnknown... How do I use it?