Isay kehtey hain na official procedure. I remember Indian sitcom office office in which a main character visits local office for issuance of his father's death certificate. The concerned person said in order to issue death certificate you must provide us the birth because it is obvious that your father died so he must have been born some years before. Anyways, FPSC should see that MS-office level literacy is even in 10 year literate child. And if a person can program in C++ or Java or knows about databases and networking it is purely ill-logical to ask such certificate. You go to some private computer institute and request them to give you certificate with clearly mentioning the name of institute and write "MS-Office" on it. Also go to your department/university and get a certificate that you posses proficiency in MS-Office. Send them both certificates and get tension free. I am asking you both because you never know they may reject one but there should be one as backup.