I'm having some difficulty in creating a monochrome mask to be used in
creating a transparent image on a picture box.

Before I get to the question let me explain how I did manage to create a
transparent picture box......

1. I created a source PictureBox (SRC) that contains a color image with a
transparent color of pink.
2. I used the paintbrush program to convert the same image to B&W.  I
changed the pink color to black and the rest to white.  I saved it as a
monochrome bitmap (note: it tried saving as a color bitmap and it didn't
work).
3. Back in VB I created a mask PictureBox (MASK) and used the monochrome
bitmap as the picture property.
4. I used the Blt function to make the transparent bitmap using my SRC,
MASK, and destination PictureBox (DEST).

This worked!

Now I tried the same thing but instead of using paintbrush I did some brute
force code to convert the SRC over to the MASK (using the PSet method).
The MASK image looked exactly like the bitmap I created using paintbrush so
I thought it would work with the Blt command......WRONG!
I also setting the MASK.picture = MASK.image but that didn't work.

So, after all of that my question is:

Can I use some API's to create the monochrome image on my MASK picture box.
How do I do it.  I've been trying for a while now and just can't do it.  I
won't complain if you bore me with details on how to do this.

Thanks,
Sam