D:\temp>mm [TCG]GGGG[AT] AGGGGC
A !~ [TCG]
G ~~ G
G ~~ G
G ~~ G
G ~~ G
C !~ [AT]

D:\temp>mm [TCG]GGGG[AT] TGGGGC
T ~~ [TCG]
G ~~ G
G ~~ G
G ~~ G
G ~~ G
C !~ [AT]