I came across a posting on http://businessintelligence.ittoolbox.com that discussed adding an editable comment box for a Cognos Report Studio report.  
Here is how this could be implemented in Cognos 8 by using .ASP pages.
- Update your database source to      contain an additional column named “Comments”.
 
- Update your Framework Manager model      to have an updated Query Subject that contains the new “Comments”      column.
 
- Generate a sample report from      within Report Studio named “InteractiveComments” that contains      an HTML Item that references an .ASP page.  You can display the comments      by dragging the “Comments” model item to your report page.
 
For example, <a href="http://localhost/cognos8/samples/InteractiveComments/Comments.asp">Add Comments</a>
- Using Notepad, or a HTML editor,      create an .ASP page called “Comments.asp” that has a submit      button with the form action to post to “Results.asp”
 
- Create the “Results.asp”      .ASP file, which will contain your .ASP logic for inserting the recordset      to your database.  There are many sites on the web that can help you with      this task.  (http://www.aspx.com, http://www.webmonkey.com, http://www.w3schools.com) 
 
On this page you should also add a hyperlink reference back to the Cognos Connection location of your Report Studio report.   
For example, Click <a href="http://localhost/cognos8/cgi-bin/cognosisapi.dll?b_action=xts.run&m=portal/report-viewer.xts&ui.action=run&ui.object=%2fcontent%2fpackage%5b%40name%3d%27GOSR%27%5d%2freport%5b%40name%3d%27InteractiveComments%27%5d">here</a> to return to the report.
- This process can be done using      any web scripting language, and I would also recommend making sure that      you are able to associate an ID value to the report’s comment.