Making a list of all combinations of 2 letters and 4 numbers

I have been trying to create a code that can make a list of all combinations of 2 letters and 4 numbers

EX: aa1111, ab1111

the only thing that i can come up with are programs that print combinations that are against my outline

EX: aatc9e, gj3ru7

What can I do that makes it so it stops at two letters and goes to the four numbers?