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: ['5481', 'W', '1285', 'U', '6155', '1505', 'Z']

5481, 23, 1285, 21, 6155, 1505, 26