ActiveX Controls have been deprecated by Microsoft in the latest versions of the Windows operating system in favor of the DotNet framework and its controls.
While MAXScript still supports ActiveX controls, these have to be installed and registered on the system to be accessible to MAXScript.
As a replacement of ActiveX controls, MAXScript supports DotNet controls in 3ds Max 9 and higher.
The loadPicture method provides a return value to be used as icon in ActiveX Controls.
Return value is a IPictureDisp, an MSDispatch object. File type must be a .bmp, .wmf, or .ico format. Anywhere an activeX control accepts IPictureDisp, you can pass the return value from this function. See the new Named Selection Set dialog and the How To ... Develop a Scene Browser using TreeView ActiveX Control - Part Two tutorial for example usages.