It is outside your control to convert a trap OID to a poller OID. It is a function of whether the MIB has a pollable OID that provides the information equivalent to the trap OID, i.e., it is up to the vendor's implementation of the SNMP Agent.
With respect to your main objective of being able to trigger an NCM action in response to a trap, that is standard functionality of NCM. You will need to define a rule from the Trap Viewer on the NCM server to define under what condition you want to trigger this NCM action. There is a section in the admin guide for Real-time Config Change Detection that covers that.
