ExcelBanter - html markup to add comments to excel cell

Please can anyone tell me how to specify a comment to an excel cell in html.

I want to create an html string such that if I just paste that html string
on excel sheet it will add a comment to one cell. This is just like how we
define formatting to a cell. for eg I can define formatting to a cell using
the below html string :

<html
<head
</head
<body
<table
<tr
<td13
<td STYLE="vnd.ms-excel.numberformat:$#,##0.00_);[Red]($#,##0.00)"41/4
<TD STYLE="vnd.ms-excel.numberformat:0.00"123.895
</table
</body
</html

Any help will be gratefully recieved.

Nitin