You can use the script I gave you earlier to do both at once.
For i=5 to Range("F65536").End(xlUp).Row
if left(cells(i,6).value,5)<>"M0000" then
if right(cells(i,3).value,len(cells(i,6).value))<>cells(i,6) then
cells(i,3).interior.colorindex=3
endif
else
if left(cells(i,3).value,len(cells(i,4).value))<>cells(i,3) then
cells(i,3).interior.colorindex=3
endif
if cells(i,4).value="" then
cells(i,4).interior.colorindex=3
endif
endif
next