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: ['D', '9499', 'R', '1917', '8269', 'Q', '8621', 'V', '4261', '3429', '8517', 'K', '4563']

4, 9499, 18, 1917, 8269, 17, 8621, 22, 4261, 3429, 8517, 11, 4563