Lookup formula question:adjacent column

I have a column with 11 different numbering schemes that go from 736466.01 through 736466.11 In the group from 736466.01 through 736466.07 I need to have the adjacent column look to those cells and if it finds 736466.01-.07 return "CM" if it is 736466.08-.11 I need it to return "TC". I created the formula below but it doesn't like something I have done unless I change the format of the 736466.xx to text. Anything other than 736466.01-.11 should return a "null" or "void" Can you help me improve this formula, or show me a better way of creating it?

Thanks,

Chris

=LOOKUP(E2,{"736466.01","736466.02","736466.03","736466.04","736466.05","736466.06","736466.07","736466.08","736466.09","736466.10","736466.11"},{"CM","CM","CM","CM","CM","CM","CM","TC","TC","TC","TC"})