Hi guys

I am working on a large worksheet where multiple sheets affect each other and I've hit a snag.

In one spreadsheet I have a series of unique numbers beginning with the letter 'E' that populate one of the columns. In sheet two I have two columns that are populated with numbers.

I want the letter 'E' to update to 'C' when cells in BOTH columns in sheet two are populated.



I've created a Test spreadsheet to demonstrate what I'm after and what I've done so far (image attached)

I don't necessarily want to use the SUBSTITUTE formula or really anything in columns L and M, it just seemed the closest formula to do what I need.

Thanks in advance for your help.

printscreenTEST.png