If you use cut & paste, instead of copy & paste, that will preserve sheet references in the formulae. Of course, that's a bit of a limitation if you want to retain the original - which case, simply copy & paste it back from the destination to the source! Now your formula on the source sheet will have their sheet references too, which means from now on you can copy & paste.

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Cheers,
Paul Edstein
[Fmr MS MVP - Word]