How do we set 'file name' value for '$FILE' attribute while Drag and Dropping from an external application into lotus Notes Document

We have an web application which permits DnD to Desktop / other applications. On Drag n Dropping a file from our app to Lotus Notes, we observed that the ‘File Name’ value in the $FILE attribute under ‘Document Properties’ refers to a random number(say 7608765.doc ) instead of the attachment name.

While the same thing works when performing DnD to the Desktop and from the Desktop into Lotus Notes Document.

Is there any specific field that we need to set in our DnD code while performing the DnD, to reflect the proper ‘File name’ in $FIELD attribute ?

However, the attachment name reflects the name of the file dragged n dropped.

Any suggestions ?