Definition: In this task, you are given an input list A. You need to convert all the alphabets in the list with a number representing their position in the English alphabet. E.g., replace A by 1, B by 2, a by 1, b by 2, and so on.
Input: ['6723', '6375', 'u', '685', 'D', 'Q', 'T', 'X', 'J', '5399', '8329', 'E', 'v', '3487']

6723, 6375, 21, 685, 4, 17, 20, 24, 10, 5399, 8329, 5, 22, 3487