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: ['r', 'C', 'Q', 'f', 'S', 'Z', 'l', '7629', '2891', '9189']

18, 3, 17, 6, 19, 26, 12, 7629, 2891, 9189