Hello!
I require what I expect to be a lengthy macro to do the following:

Cells to be replaced within SheetX, Section E2:BN135000
Search within SheetY, Section A2:BP980000 (as you can see I'm dealing with a huge amount of data)

I need the macro to go row by row. If any cell from Column A within SheetX matches SheetY, then it also needs to confirm within those same rows that Column B, C and D match up. If yes, then it will replace from SheetY cells E, F, G ..etc the cells from columns E, F, G, ... BO in SheetX.

The rows #s do not need to match. So for example:

In SheetX I will have multiple rows in Column A that say "Dog". So SheetX.Row25.ColumnA = "Dog" and SheetY.Row333.ColumnA = "Dog". Then it should confirm if Columns B, C and D from SheetX.Row25 and SheetY.Row333 also match up.
If Yes, then SheetY.Row333.ColumnsF,G,H,K,L,M,O,T should replace SheetX.Row25.ColumnsF,G,H,K,L,M,O,T ....(also what if the columns are not together in a range and some need to be skipped? how could I implement that)

Please help at all if you can. Most of the responses I have found so far on multiple find and replace don't provide much for cross refenencing and validating matching cells.

Thanks!