The channel name and channel comment are two vector variables called CN and CC. You can access each channel either by using its number in the channel list (e.g. CN(1)) ir its name (e.g. CC("Time")).
You can simply use lines like this to change a comment:
CC("Time")="Hello"
This will change to comment for the "Time" channel to the string "Hello".
Hope this helps,
Otmar
Otmar D. Foehner