Well, I think Dark Basic Pro has a lip-synching add-on - never looked at it, but it may just contain code you can port across to Blitz.
EDIT:
Here it is http://darkbasicpro.thegamecreators.com/?f=dark_voices
I've not read this page prior to posting it.
EDIT:
Here it is http://darkbasicpro.thegamecreators.com/?f=dark_voices
I've not read this page prior to posting it.