problems using COM with Visual C

[Jim Kerr]

  I'm trying to use Python's COM facilities to control a build in Visual
C++.
I've run into some problems that don't make sense to me at all (not
surprising,
since I don't know COM).

  Here's the script I have so far:

     # Open and manipulate a Visual C++ project

     from win32com.client import Dispatch
     vc=Dispatch("MSDEV.Application")
     vc.Visible=1
     vc.Documents.Open(r"C:\src\Workspace.dsw")
     projlist = vc.Projects
     ap = vc.ActiveProject()

  So far, so good; ap has the value 'MainApp', as it should. But if I
try to set the active project (from PythonWin)

    >>> vc.ActiveProject = 'Persist'

... it doesn't fly:

Traceback (innermost last):
  File "<interactive input>", line 1, in ?
  File "C:\Program Files\Python\win32com\client\dynamic.py", line 413, in
__setattr__
    self._oleobj_.Invoke(self._olerepr_.propMap[attr].dispid, 0,
pythoncom.DISPATCH_PROPERTYPUT, 0, value)
com_error: (-2147352567, 'Exception occurred.', (61837, 'Microsoft Visual
C++', 'Unable to write read-only property.',
'C:\\PROGRA~1\\MICROS~3\\COMMON\\MSDEV98\\BIN\\MSDEV.HLP', 455053, 0), None)

  The MSDEV documentation sure implies that ActiveProject is writable, so
this
error seems kind of confusing.

  So anyway, I'm doing something wrong... I can accept that. But here's the
odd thing:
from this point on, no matter what I type at the PythonWin prompt, a dialog
appears
that says:

  'The topic does not exist. Contact your application vendor for an updated
   Help file (129)'

  The only cure that I've found for this is to quit and restart PythonWin.

  Has anyone out there slayed these dragons before?

  FWIW, here are some OS and Python specifics:
    NT 4.0, Service Pack 5
    PythonWin build 125

  Thanks for the help!

-Jim