A family of Microsoft word processing software products for creating web, email, and print documents.
I believe that it would be possible to automate the whole scenario using Visual Basic, but using the software as it comes "out of the box" there are only some parts of it that can be done.
For example, you can use If...then...Else fields in a mail merge to interrogate the contents of a field in the datasource and then insert different text into the document, depending upon the contents of that field.
It is not clear what the "outcome that I have chosen" means and in what way the selection would be made on the basis of that outcome, but it may also be possible to handle that by the use of If...then...Else fields.
What cannot be done with mailmerge is the updating of the spreadsheet.
However, as mentioned, it is possible to automate the process to perform some quite complex processes. You can see some examples in the MergeTools add-in that you can download from by Windows Live SkyDrive at:
https://skydrive.live.com/?cid=5aedcb43615e886b#cid=5AEDCB43615E886B&id=5AEDCB43615E886B%21111