VLOOKUP(lookup_value,table_array,col_index_num,ran ge_lookup)

If I use MONTH(TODAY()) in place of col_index_num, I am getting an error.

I have also tried TODAY() in cell A1, MONTH(A1) in cell B1 and
B1 in place of col_index_num. I still get an error.

Is it allowed ? Is there an alternative?

Thanks in advance for any valuable guidance
Hamsa