Read adjacent cells and replace value given conditions

[neuromorph]

I want to read a table and change all cells that do not have a pair of [AAA,AAA] with other content. So reading the first row, the [AAA,CCC] cell will be read and converted to [AAA, XXX]. The table has a dead column of data, like column 3, that doesnt need to be read. All AAA values will be maintained and any AAA unmatched pair should change the non-AAA cell to XXX.

i hope this makes sense.

1	2	3	4	5
AAA	CCC	DDD	AAA	AAA
AAA	AAA	DDD	BBB	AAA
BBB	AAA	DDD	CCC	BBB
AAA	BBB	DDD	AAA	AAA

 

[neuromorph]

This is to make a map in excel, no computations needed, just looking for a way to changing elements other than manually, or conditional highlighting.