compare column a with Column a

Excel Macro:

Is there a way to show the exact message (Message column) after clicking a COMMAND Button?

Column B
B2: Yes
B3: No
B4:

Column C
C2: No
C3:
C4: No


Column D (Message)
D2:Column B is not required
D3: Column C is requred
D4: Column B is requred

Thank you