I have never tried to do that, but I can imagine the problems you will encounter.
Well someone has tried, and wrote a free short course in microscope photography:
http://www.shortcourses.com/how/microscope/microscope.htm
Maybe there is something to be learned by reading what he wrote.
...
..
.
I just purchased a Canon PowerShot A620. It
performs fine in all normal manners but I attempted
to adapt it to my Baush & Lomb binocular microscope
utilizing the microscope eyepiece, I can't obtain
a good resolution image. focussed image at eyepieces fine,
tried various wide field 10 and 5 power eyepieces-- and one with extended eye relief--same problem. Tried manual focus on camera, various zoom settings, vignetting not a problem, but images
are abot half the resolution that the camera is
capable of. Is there an intrinsic problem in
adapting this camera for microscope image recording.
Using remote shooting via computer gives same poor
result. Need help-excellent camera otherwise
Alherm

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic