Hey guys. First time posting

So I have an excel file that I use for scheduling. I have it set up in a Gantt layout. I need to mirror the exact data I have into either another tab, or directly below it in the same excel file. The problem I am running into is that when I update the "Main" schedule and I select multiple cells and merge, I need the "mirrored" version to duplicate that for me as well.

So if I have Data in cell A1 and cell D1 is mirrored, any data I place in A1, D1 will duplicate with the simple =(A1). But what I need to know is when I need D1:D5 to mirror A1:A5 only when I merge A1:A5.

I hope this makes sense and I hope excel can do this. I just don't want to have to do the same thing to two different schedules.

Thanks!