For getting the new columns I would prefer doing it as following:
df['Country'] = df['A'].apply(lambda x: x[0])
df['Code'] = df['A'].apply(lambda x: x[1])
df['Com'] = df['A'].apply(lambda x: x[2])
As for the replacement of , with a . you can use the following:
df['A'] = df['A'].str.replace(',','.')