Look at here :
and yes FD comes with english voices.
If you dont know how change :
2 soluces :
first : no more english
rename your sweedish voice pack in All
delete and replace
Edit : don't know why : it's voice and not voi ce but can't correct ?
second : keep english voices
copy your sweedih directory in
then select your new pack with C:\DestinatorApps\Destinator\C_client.exe
select menu, Create destinator's dialog then look and feel and go !