Cannot get accurate results from Hittest
 

Trying to write a routine that drags and drops from a listbox to a
treeview. However the hittest scaling is out.

First realised that X,Y values were in twips and hittest worked in
pixels but the scale is still out. My pixels-twips convertion is using
GetDeviceCaps reading the pixels per inch value but that is wrong.
Then wrote a routine using GetDeviceCaps referring to screen width and
screen resolution and doing the calculation itself but the result is
also wrong (screen width reports the wrong size of screen).

Does anyone have any suggestions? Using Excel 2003 and vista rolled-
back to XP.