Reading a Cobol (.cbl) file in python and extract the commented lines from it

Question

I am having a .cbl file with many lines. I want to read it and extract the commented lines form the same into a .txt file.

For example:

a.  000200* PROGRAM-ID. AP540P00.
(or)
b.        * PROGRAM-ID. AP540P00.

I need to check for * at 7th position. After extracting all the commented lines print it to a text file.

I did this:

with open('AP540P00.cbl', 'r') as f:
    for line in f:
        s = set(line)
        if ('*' in s ):
            print(line)

But I need to specifically check * only at 7th index of every line.