How can I change character in string?

I have strings:

11QJB10(11|12.13|14)AA001|11QJB11|(12|13|14)AA00212KAC31(32)AA001|003|12KAC33(34)AA001

I need to change symbol '|' before 11QJB or 12KAC to '@'

I do:

code = re.sub(r'\|(?=10[A-Z]|11[A-Z]|12[A-Z]|L)', "@", code) 

It does not work.