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: ['7869', 'q', '7887', 'z', 'r', '7069', 'C', '2793', 'N']

7869, 17, 7887, 26, 18, 7069, 3, 2793, 14