Is there anyway to have a CRA transfer to a huntgroup (21111) pause and then dial a 4 digit string? I'm thinking something like CRA Action 2) Transfer to extension 21111,,,8430

I've got individuals CRAs and Hunt Groups for each extension so that if the phone is busy the caller will get a repeating message allowing them to hold (timeout) or leave a message (opt 2)or reach the operator (opt 0). Opt 2 transfers to the particular mailbox for that extension. I'm wanting to integrate my Exchange 07 UM server (instead of the Inter-Tel). The Exchange UM server is located on a analogue voicemail hunt (21111). With a regular system foward (system foward #2), calls get routed to the appropriate mailbox. My delimma comes in, in trying to get calls to the correct mailbox from a CRA which doesn't seem to pass any extension information. My CS-5400 and AudioCodes Mediant 1000 are connected via T1-CAS. Any ideas? I really want the Exchange UM, but I've invested too much into my overly complicated holding applications (each extension has a dedicated system foward, CRA and hunt group)to give them up.