Two things must be understood very clearly:
1) Global politics is governed neither by some kind of moral values nor by certain sense of justice and fair play. It is straightway ruled by the principle of "Might is Right". The influence, a state wields, is directly proportional to its economic, technological and military resources.
2) UN is not at all some kind of body to provide justice to its member states; but to preserve, in an orderly manner, the respective interests of states, not on the basis of equality, but again somewhat proportional to their aggregate power. To exemplify, UN is a well attired concubine, which distributes its favors and entertains, in accordance with the respective influence, power and wealth of the "Tamaashbeens" or members.
If Pakistan wants UN to not to act against its national interests; it will have to gain and acquire wealth and power. There is no shortcut to it; rest is merely "Randi Rona".
"Lissay da ke zor Mohammad, nas jaana ya rona"
(Mian Mohammad Bakhash in Saif ul Maluk)
Case of Maulana Masood Azher need to be seen in the above perspective. Discussing it in certain moral framework is utterly futile and useless.