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: ['I', '6797', 'O', '447', 'o', '1667', 'u', 'V', '6209', '3213', '9019', 'd', 'P', 'i', 'C', 'd', '7275', '1473', '5619']

9, 6797, 15, 447, 15, 1667, 21, 22, 6209, 3213, 9019, 4, 16, 9, 3, 4, 7275, 1473, 5619