How use the PreviewDocx64 routine?

Hi,

   I try to use the routine PreviewDocx64 in my Add-in and I don't have any idea How can I do it?. Do you have any example or something else?

PreviewDocx64 needs a HWND but ... "longlong *" and I don't know what is it, I've only got a Window's HNWD but don't works :-(

Many, many thanks in advance

Josemi

Windows 7 x64

Solidworks 2012

SolidworksApi macros