How do I set a route through a table in Word

[jeffro_imms]

I need to set a route through a table that I have created whilst protecting
the Subject fields from being overwritten

 

[Suzanne S. Barnhill]

What you are describing is a protected form. See
http://word.mvps.org/FAQs/Customization/FillinTheBlanks.htm and especially
the forms tutorials by Dian Chapman that this article links to.