Hi Aude,
You can use Word's Catalogue/Directory Mailmerge facility for this (the terminology depends on the Word version). To see how to do so with any mailmerge data source supported by Word, check out my Microsoft Word Catalogue/Directory Mailmerge Tutorial at:
http://windowssecrets.com/forums/sho...ngs-(2000-2010)
or
http://www.gmayor.com/Zips/Catalogue%20Mailmerge.zip
The tutorial covers everything from list creation to the insertion & calculation of values in multi-record tables in letters. Do read the tutorial before trying to use the mailmerge document included with it.
For a recent, worked example, see the attachment to post #13 at:
https://www.msofficeforums.com/mail-...nt-dollar.html
Alternatively, you may want to try the Many to One utility on the MergeTools Add-in that you can download from the following page of Doug Robbins' Windows Live SkyDrive:
https://skydrive.live.com/?cid=5aedc...615E886B%21111