[NTG-context] Form with character separators

I would like to produce a form with a character separators. However, my code presents two problems: first, the character box has no fixed dimensions and, two, I can't indent the text when it occupies multiple lines (ex, address field). I tried to use the starttabulate environment, but without sucess. My questions are: Can I fix the size of the boxes? and Can I apply the starttabulate environment to indent the field description and align all descriptors and fields names (name, age, sex, race, address, ...)? Thanks in advance Jorge