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: ['4673', 'd', 'u', '8773', 'j', 'A', 'z', '811', 'u', '5699']

4673, 4, 21, 8773, 10, 1, 26, 811, 21, 5699