how to deliver SRV Records content according with the query requester source Ip.

Can I deliver the query to a SRV Record by source IP? I need to deliver different content on the Target Server according with the country that request the query, so I need to change the destination record according with the source IP. I can see how to do it with A records, but I never see anything similar with SRV records. This is mainly to hold VoIP traffic inside their own area.

Thanks,