[GNC] Changing account numbers?

[Dan Rawson]

   I have a VISA account with my bank where the number has changed (the
   bank replaced the card).  The latest downloaded transactions obviously
   have a different account ID in the OFX file; is there any way to
   persuade GnuCash to treat this a all part of the same account?
   Currently, if I try to import the OFX, the transaction matcher doesn't
   find anything . . .
   A scan through the doc/wiki/faq didn't turn up a solution :-(
   I can obviously set up a second account, but that's not ideal from my
   point of view, and it's not how the bank treats the account; all the
   transactions both before and after the card swap are part of one
   account as far as they are concerned.
   Thanks in advance . . .
   Dan