Hi Tina,
I found it !, I was missing one step before closing the
comunication, that was:

=DDEexecute(ChanNum,"SendfaxUI")

"SendfaxUI" will instruct delrina to start sending without
issuing a "print" from the application, I found this at
Delrina's web site, and this command is not in the help
file that comes with Delrina nor in the manuals. They have
also another undocummented commands. I still have to click
on 'send', but at least it brings the 'Send Dialog' from
win fax, and I don't have the blank page on each document.
Save this for the future you might need it when you receive
your 'Win Fax pro', it makes sending faxes really simple from
within Fox.
=THIS.parent.thanks_again('very much')
luisg@netrunner.net