redirect .com to .com.au without knowing dns

Any Ideas blackhatters?

Iv'e got a dentist as a client iv'e built his website with .com.au domain name.
He already had an old site .com same domain name.
He hasn't paid anything for 5 years doesn't know where it's hosted doesn't know were it;s domain name is stored.
Said he built it him self at econcentral dot com i can't find that site at all.
I want to redirect that site to the new domain for the google postion it has!
Is there a way of doing this with bugger all info?

Cheers

Gerry