Expanding on TE,
Do you have spare SL and LS ports?
Could you loop back an SL port with an LS trunk (or 2) and then have the trunks answer position as a CRA with the announcement.
When you want to conference in the recording you could conference in the SL extension which will ring the trunk and answer with the CRA.
If you want multiple recordings you can probably have silence as the audio and then options 1, 2, 3 etc... to play different CRA's again so that minimal SL/LS ports are used.