Can I define several number ranges and groupings in CRM?

Hi,

Can I define several number ranges and groupings in CRM?

For example:

Number Ranges:

01 1--1000 Internal

02 1000--2000 External

03 3000--4000 Internal

04 4000--5000 External

Groupings:

0001 internal1 01 Internal

0002 external1 02 External

0003 internal2 03 Internal

0004 external2 04 External

Thanks a lot!