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: ['P', 'W', 'j', '6357', '9283', 'O', 'l', 'D', '8589', '2199', 'X', '9731', '1923']

16, 23, 10, 6357, 9283, 15, 12, 4, 8589, 2199, 24, 9731, 1923