Sqlite3 Updating Row Defined by a Variable

Not sure if I phrased the title correctly, but basically my question is is it possible to have sqlite update a row which is defined by a variable? For example:

db.execute('''UPDATE CUSTOMER SET ? = ? WHERE CUSTOMER_ID = ?''', (title, info.get(), k))

where 'title' (the first question mark) is the name of the 'row' I want to update within the table Customer. I have tried the above code but it doesn't work. Does anybody know if it is possible to do this with sqlite3 in any way?