Windows XP encoding for non-english and english characters

The problem, obviously, is that the text I was trying to write contains characters that are not included in the encoding.

To solve the problem I tried to replace all the "bad" characters with normal ones. In order to find to find all these characters I used the following script

bad_chars = []
with open(name, 'w', encoding = 'cp1253') as res:
    for i in range(len(whole_text)):
        try:
            res.write(whole_text[i])
        except:
            bad_chars.append(whole_text[i])

Then I created a dictionary with the correct characters and I replaced them in the text.

chars_to_change = {'∆':'Δ', 'Ω':'Ω', '₂':'2'}
for c1, c2 in chars_to_change.items():
    whole_text = whole_text.replace(c1, c2)

Note that there might be better solutions, especially in the first part of the solution. Please edit if you find an improvement or error