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: ['e', 'l', 'F', '7213', '1999', 'L', 'C', 'i']

5, 12, 6, 7213, 1999, 12, 3, 9