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: ['6447', '9993', '2147', '9653', '6323', 'n', 'C', 't', 'G', '7235', 'R', '7577', '6951', '8207', 't', 'h', 'b']

6447, 9993, 2147, 9653, 6323, 14, 3, 20, 7, 7235, 18, 7577, 6951, 8207, 20, 8, 2