Yes a ; is a comment mark - as for the parameters those are what are passed into the UDF

In this particular case
AddPrinter(192.168.0.100,"HP400M","C:\Drivers\HP.INF","Secretary Pool",,1)

Would add a printer on port 192.168.0.100 The Inf file would have the printer listed in it as HP400M and the INF file is located at C:\Drivers, the description on the printer is Secretary Pool, it will be installed on the local machine and will be set as default.

Does this help?
_________________________
Today is the tomorrow you worried about yesterday.