Fill a multiline form field with proper line wrap

A form that is meant to be printed and filled via handwriting provides a field for a multiline value that can be filled by long text. It is rendered like this:

+-----------------------------------+
|                                   |
| --------------------------------- |
|                                   |
+-----------------------------------+

So there are two lines with a horizontal rule as guidance for filling the value. I can create this easily with

documentclass{article}

begin{document}
fbox{
  begin{tabular}{p{10cm}}
    rule{0pt}{1em}  hline
    rule{0pt}{1em} 
  end{tabular}
}
end{document}

However, I now want to add the possibility to fill this field from inside LaTeX, so that it is rendered like this:

+-----------------------------------+
| Lorem ipsum dolor sit amet, con-  |
| --------------------------------- |
| sectetur adipiscing elit, sed do  |
+-----------------------------------+

i.e. I want to give a continuous text value and want LaTeX to properly place it inside the existing lines like a paragraph, with proper word-wrap and spacing. The rendering should otherwise be identical to the empty variant (it is okay for values to destroy the layout if they are too long).

I figure to do this, I would need to throw away the tabular and use a minipage or something that draws horizontal lines between the text lines. At the end of the text I would need to fill additional horizontal lines if the text was too short to produce all expected lines.

How can I do that?

To avoid misconceptions: I do not wish to generate an interactive form of any kind.

documentclass{article}
usepackage{multirow}
begin{document}

  begin{tabular}{|p{6cm}|}
    hline
    rule{0pt}{1em}multirow[t]{2}{=}{renewcommand{baselinestretch}{1.1}normalsize
        Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do}
     hline
    rule{0pt}{1em} 
    hline
  end{tabular}

end{document}