Appending Data to a feild (Access 2010 Web Form) (1 Viewer)

I have an Access 2010 Web Database deployed to SharePopint via Access Services. In my data entry form there is a comment block that needs to be updated based on a new entry to a test box. I use a button that inserts the Date and Current user in front of the text bos entry and then adds the text box entry to the [Comments] block. What I need is a way to add a carraige return/line feed after the Date and user name and between the new entry and the original entry so it ends up like this:

12/3/2013 UserName

{New Comment added here}

{Old Comment}

Can anyone help me out? Can it be done?

Would it be possible to get the unique primary key field, use that to execute an update query against the table?