Is it possible in Call manager 10.5 to forward calls that are received from a certain extension but allow all other calls to be received as normal or to block calls that are transferred to a certain extension to another extension.
This parameter determines whether Cisco CallManager ignores call forward all (CFA) destinations when the CFA destination is the same as the calling party number. For example, John (on Phone A) has CFA set to Jane (on Phone B). With this parameter enabled, Jane has the ability to transfer a call to John's phone without having that same call sent back to Jane due to John's CFA setting. This capability proves useful when Jane receives a call forwarded from John's phone, but which must go back to John's phone so that the caller can leave a voice message for John. If this parameter is set to False, Jane cannot send any calls to John's phone and the caller will not be able to leave a voice message for John. Note: This override capability only works when the calling party number matches precisely with the number specified in the call forward all destination. In cases where the calling party number has been transformed, the calling party number may not match the CFA destination and override will not be allowed. Valid values specify True (CFA overrides are permitted) or False (CFA overrides are not permitted).
What you're looking is the concept of white/black lists which is not something CUCM has.
About transfers, no such thing either, the same CSS you use to place any calls is the one you use for transfers.
