Hi,
There several CWDIO examples written in VC++ at the following ftp site:
ftp://ftp.ni.com/support/compworks/samples/
Look for the zip file CW3VC.zip
You'll be able to see the syntax you're looking for in the in the examples under the DAQ/DIO and DAQ/ReadWrite folders. Just note that these were written with CW 3.0.
Regards,
Azucena