Mass Find Replace.xlsm

I need a macro to do a mass find/replace loop on the tab "reimported" Column A Values replacing to Column C values

Please see attached as it is difficult to explain.

I get data from the database and run a formula to extract the hashtag contained within.
If no hashtag is present I will get an error.
I then copy and paste all the errors to the export tab and remove duplicates.
This tab gets emailed for correction.
The user then resends the tab and i copy it into Reimport tab.
I then need a macro to go row by row Finding the data in column A and replacing the data in the Data tab with Column C thus correcting the errors.

Thanks

Rob