You need to try using a three manual sample set. St Anne’s is a two manual organ.
You can only reconfigure organs by using HWs CODM facility.
See http://www.hauptwerk.com/clientuploads/ ... rGuide.pdf
Look at http://www.piotrgrabowski.pl/friesach.html this is an organ which is “free” but you are asked to donate to support the work. With the free edition of HW you will need to choose which stops to load to remain within the limit on the size of instrument which works with the free edition. You’ll probably keep hitting this limit if you want larger instruments perhaps you need to consider buying the basic edition.
Iain