When searching the net to give you more information, i found this in http://msdn.microsoft.com/en-us/library/windows/desktop/aa394366%28v=vs.85%29.aspx :

DependentFiles

Data type: string array
Access type: Read-only
Array of dependent files for this printer driver.

Uuups, seems that I should have read this first... (Access type: Read-only)!!!

But nevertheless thanks for your prompt answer.