Dana,

You can link a series a text boxes so one will overflow to
the next but I don't think they will expand.

You can insert and format a frame that will expand with
text.  Tools>Macro>Macros.  In the Macros in window select
Word Commands. Scroll down and find InsertFrame and hit
run.  This will give you a crosshair cursor to in the
document to draw the frame.  You and right click and
format the frame to add background and borders.

The insert frame command is also located on the standard
Forms toolbar.