Vlookup

How do you solve the following;

If the range_lookup argument is FALSE, VLOOKUP will find only an exact match. If there are two or more values in the first column of table_array that match the lookup_value, the first value found is used. If an exact match is not found, the error value #N/A is returned.

For example if I would like the function to read from something called TX1, TX2, TX3 and TX4, and then I add TX up to TX14, then the function will read 14 as 1 (the first digit in the number).