How to generate multiple terms argument

Hi all,

This seems like it should be easy, I must be missing something.

I need to dynamically filter a view using an argument. The field the argument is based upon is a CCK text field. I need the filter to allow for multiple terms, but the views "Configure Argument" dialog doesn't seem to have the checkbox "Allow multiple terms per argument" for a text based field. How can I create a multiple term argument for a text based field?