Lookup tables for custom fields

Hi, I am using PS 2007 environment.

I got to create a project level enterprise custom field and associate a lookup table for that field

If i create a look up table, how do i need to do that if my values in look up table would read as

1.1.2.0

1.2.2.0

1.3.3.0

Currently i have

Type=text: code preview=0: sequence=number: length=any: separator=. :

and providing values as this throws an error "

• One or more code values in the lookup table contain a code mask separator.

Thanks

MP