How to include an ActiveX control in a GridPanel to detect a drag and drop event?

Hello,

How can I include an ActiveX control in a column of a GridPanel that would detect a drag & drop event? My goal is to perform a postback when user drag and drops a file from the desktop into the ActiveX control. What is the best way to achieve this in ExtJS (version 2.5.03.. or higher.). We were able to do this in the previous version of ExtJS (version 1.xxx) but now we're getting a runtime error. I should add that the our ActiveX inherits from WebControl and implements IPostBackEventHandler and is wrapped inside an <Editor> in a column.

Appreciate any help.