i think i got it right.

I removed the addprinter entry and saw that the printer is still avaliable in the terminal seessions. So i removed the delprinter and addprinter entries and added the below.
SetDefaultPrinter("Bro-HL1440"). I checked with few of the users and it seems that Bro-HL1440 is now the default printer.

Thanks NTDOC and Lonkero very much for you help and assistance.