Use the feature code Converse data return code when working with an IVR. You must have the call vectoring prompting features turned on. If you do have it turned on, it will be on page 5 of disp feature-access-code. Not sure if it is on the money page or not... But if you don't see it in disp feature, look there...
If my converse data return feature code was *44
The IVR dial string would be *44 then your VDN..
I speak from experience as I just did this last week...
Hope this helps.
Thanks,
Wildcard