To be honest, I'm not sure I understand your problem.
I expect Master equivalates an Excel Sheet!
If you would like to check whether a value in one cell corresponds to a value in another cell may use this approach:
If Sheets("Master").Range("A1").Value = Sheets("Slave").Range("A1").Value Then
Else: MsgBox "Not found"
But if you don't know which colum to compare with, you'll first have to identify the column.
You need to look for a value you know exist or maybe it's enough for you to determine whether a value exists at all.
You may do this by looping rows or columns.
I don't know if this is your problem. I have to leave now, but if you havn't got an answer I'll be glad to try helping tomorrow. I'll look into this site then.
If you're fairly new to Excel, which I'm not sure you are, there might be something interesting here: