Search Row By Column Value And Highlight Text - For Each Row

I've got a large Excel table that's full of names and e-mail addresses - it's a report of e-mails that merges some data from two systems we use; a registration form and a database. We want to clean up the data so it only lists folks who 'registered' (it's not always BOTH people listed - sometimes it's only one!) - and the best way to do that is to take the information from a specific column in each row, see if it exists elsewhere in the row and clear the information that doesn't match.

For example:
-A----------------B------------------C--------------------D--------------E------------------F-------------------G-
John ---------- Smith -------- js@email.com -------- Jane -------- Smith --------- js@email.com ------ John
Richard ------ McGee ---------j@email.com-----------Jim----------Samename ----jsn@email.com-------Rich
Mary-----------Ladyface ------ms@email.com--------Steve -------Smith ----------ss@email.com-------Steve

Ideally, for each row I'd like to search A and D for the string from column G. If it finds it, the cell and the two cells to the right are fine - but everything else is 'cleared' (not deleted).

So the above table would look like:
-A----------------B------------------C--------------------D--------------E------------------F-------------------G-
John ---------- Smith -------- js@email.com --------------------------------------------------------------- John
Richard ------ McGee ---------j@email.com-----------------------------------------------------------------Rich
-------------------------- -------------------------------Steve -------Smith ----------ss@email.com-------Steve