I see, I guess the host/owner of the old domain are not willing to support in terms of putting a re-direct in? I guess it depends on your CMS but we did something similar with an old help site i managed where we had to change all the internal hyperlinks of around 1.5k articles because the domain changed. We had to put the content in change freeze, export all content in *.csv, edit it using find/replace then import the content back into the system, long winded but it worked.
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