[ic] Database range-lookup question, CommonAdjust?

[interchange-users@icdevgroup.org (Interchange user)]

This may be a MySQL question; I'm not sure, but someone could save me 
countless hours of searching and frustration if they could answer this for me:

I have a custom shipping routine that currently does a lookup into a MySQL 
database table and gets a price for an exact weight.

I want to make a change so that the exact weight of the items can be used to 
make a range lookup in the table, for example:
 
weight	zone1

60	0.27
100	0.41
150	0.57
200	0.72

A weight of 1 to 60 costs 0.27, a weight of 61 to 100 costs 0.41, and so on.

Can Interchange's 'CommonAdjust' feature be used for this? If so, how? I 
noticed the 'pricing' table from the Foundation demo uses ranges such as q2, 
q5, q10, etc.

Thanks in advance.