bpw/delphi 1.0 -> 32bit

Hello everybody!

Over past 10 years I have developed a TP -> BPx ->Delphi 1.0
application that is currently being sold commercialy
(www.softmath.com, if you want to take a look), consisting
of appx. 70K lines of code. Currently the program is fine under
 Win 3.1/9x as a (very stable) 16 bit application. My problem is
of course, Windows 2000. When I ran it under Windows NT it
promptly crashed, so I am suspecting that the same will happen
under W2000. Although the software is currently working with
Delphi  1.0, it is really a pure BPW application - it uses
TWindows and other classes that can not be intermixed  with
Delphi classes. The other problem are 16 bit API calls that need
to be converted into 32 calls. I have been postponing this step of
converting to a 32 bit application mainly because of the code size,
but now I don't see any other alternative. I will appreciate any
suggestion that anybody might have on how to convert this 16
bit monster into a 32-bit one. Any automatic converters of bpw
objects, API calls out there ? Anything I can think of seems to
require at least one year of heavy duty development work that
I am not ready to put it (the program is not selling that well!).
This program has been developed (part time) over a period of
10 years, and although there are virtually no bugs in it, there
is a lot of  'midnight code' in there; I am not looking forward
to rewriting it (i.e. putting the core code in DLLs and redoing
the GUI, which is quite complex).Finally , a really stupid question,
to which I am sure that the answer is NO :  does Windows
2000 provide some kind of "win 9x box" (like MS DOS box
we used to have in win 9x)  that would run *any* 16 bit code ?
I just had to ask.

Thank you for any suggestion that you might have.
It might save me year(s??) worth of work.