Is this possible? Changing IPs in A records server wide?

[pingo]

This is probably not possible (?), anyway. I am moving 1200 web sites to other servers and has to manually change the IPs of two A records (ns1/2) in the DNS zone files. The majority uses the same nameservers/IPs but some uses their own private nameservers so the IPs of these A records are different. - Did any clever person out there write a script that browses through the zone files and changes them all in one hit?. Hehe, I'm just an optimist

Thanks
John