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: ['3879', 'q', 'd', '5647', '9765', '7993', '2823', 'd', '2709', 'H', '1791', 'C']

3879, 17, 4, 5647, 9765, 7993, 2823, 4, 2709, 8, 1791, 3