textbox2 to contain text from textbox1 in openoffice

Question

Already asked but no answer: Using OpenOffice.org Writer, one can easily make simple pdf forms (since Writer does XForms, and can export to PDF, and embed the form using FDF). I'd like to make a text entry field with this property:

* if the field overflows, put the overflow on an additional page, or in some special area on the page, labeled "Additional comments" or something
* Basically, what I imagine:
      o textbox1 = fixed size
      o textbox2 = fixed size (perhaps on another page) to contain the overflow from textbox1

I'm new to Writer, FDF, and the like, so if this is impossible, I'd be glad to hear that as well. Thanks in advance!