ok, this might sound a little confusing, but there is a way to do it. and there may be other ways, but this one is the easiest i can think of.
FIRST
download audacity.
http://audacity.sourceforge.net/latest/audacity-win/audacity-win-1.2.6.exe
audacity is a program used to record, edit, save etc. audio files.
SECOND
install it. (dont worry, theres no spyware or anything, i use it and im fine. and if you dont want to install it anyway, use Portable Audacity)
http://downloads.sourceforge.net/portableapps/Audacity_Portable_1.2.6_Rev_3.paf.exe?download
THIRD
open audacity and the speech window. type what you want into the speech window and set it to microsoft sam.
FOURTH
go to audacity and set the imput device in the drop down menu at the top to "what you hear" or "WAV out" or something along those lines. then hit the record button, quickly switch back to speech, and hit play to make microsoft sam say stuff.
when this is over, hit the stop button in audacity.
FIFTH
save the new sound from the File menu. if you are going to save it as an mp3, you will need to download a dll. thats ok.
http://www.dll-files.com/dllindex/dll-files.shtml?lame_enc
SIXTH
import the saved file into windows move maker
i really hope that helps. good luck.