[Zope] file upload to property, how to?

greetings. I have a property of type text. I want to be able to edit by uploading a text/html file into the property of a ZClass. I have it setup so that it is loaded from a file on installation (*addForm()), but to change it, the property management form only knows about textarea- or text-type input. I know how to do it in dtml, I could probably figure out how to do it in python... but, where do I do it? -- John Edstrom | edstrom @ slugo.hmsc.orst.edu