Access 2000

If I have a table with 4 columns, all are text, how would I get the data from the 4th column into a variable using the 1st column as a reference.

For example:

cnum, cname, addy, IPs
-----------------------
1234, bob, 321 st, 1.1.1.1

I need to get a variable to contain 1.1.1.1 if cnum=1234

I don't think it's too tough, I'm just stuck.