[Zope] How do I use dtml-var image tag with a string

So this is the deal, I have a URL stored in a database. This url is to an image on the site and when it gets returned I want to Do something like: <dtml-var myURL> except if I do this I just end up displaying the string instead of getting a dynamically generated image tag. So I tried <dtml-var <dtml-var myURL> > this of course errored. NE ideas? Thank you J