put two divs inside the containing div. put one at the top, the other at the bottom.
this should give you the desired effect:
<div style="text-align:center;border:1px solid black;width:100%">*** THIS IS COMPUTER GENERATED ***</div>
<div style="position:relative;text-align:center;border:1px solid black; float:right; width:200px; height:75px; ">
<div style="position: absolute; top: 0; right:0; left:0;"><b>for Covai Computers</b></div>
<div style="position: absolute; bottom: 0;right:0; left:0;"><i>authorised signature</i>
</div>
</div>
BTW, html/styles is not my area, and I’ve just hacked this together. Perhaps someone will come up with a better solution.
In manager it will appear off the page but it should print ok.
on the page: