CS_DROPSHADOW is a class style (hence "CS_") and can be applied using
SetClassLong. However, it will affect all Plus! windows as they share the same class.
Also, it only affects windows created after it is called, even though it requires a window handle. So to affect only one window you need to do something very illogical like:
- Create an invisible window
- Use SetClassLong on invisible window to enable shadows for the Plus! class
- Close invisible window
- Create your window (which will now have a shadow)
- Put the original class back so other windows aren't affected
I would code it up, but I would feel dirty doing so