Are you guys not attempting an upgrade? I can't say I've tried to upgrade from 5.0.23 to 6.4, but I don't see why it wouldn't work.
If both databases exist already and there's no chance of just upgrading, then as Tetsuji says, you'll want to get a DBA to extract the data from the first database and insert into the second.
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Dave Morris
3Ci @ Southern Company
Atlanta, GA
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Dave Morris, 3Ci at Southern Company