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: ['4491', 'z', 'd', 'C', '2099', '9717', 'l', 'z', '2703', 'k']

4491, 26, 4, 3, 2099, 9717, 12, 26, 2703, 11