salam to all css aspirants going to opt punjabi.
well,scores are always a matter of ur interest in that particular subject,hard work and last but not least ur luck.
so if anybody have an interest in punjabi,he should opt it,coz it is too easy to prepare.but what the problem the most aspirants face in punjabi is to write punjabi fluently and correctly.REMEMBER,it is only PRACTICE of WRITING PUNJABI which is the sole solution to the above mentioned only problem.but dont worry,it is just A GAME OF TWO WEEKS.
BOOKS:

1)JAHANGIR'S PUNJABI
2)ADAB SUMANDAR by DR.ASMAT ULLAH ZAHID

these two books are suffient for examination point of view.and are available at ILMI BOOK HOUSE,URDU BAZAR,LAHORE.
WISH U ALL THE BEST.
I A KLHAN (PAKPATTAN)