WMI script to fetch DELL Servicetag

I'm looking for a way to enumerate all servicetags in a active domain. Until
now I've tested a few existing scripts, but they fetch only one servicetag at
a time.

The classes Win32_Bios and SerialNumber and UserName are needed to list the
data I need.

Anyone have a idea? My knowledge of VBscripting isn't much, but I need the
data soon.

Regards,

PJH