From Tracker Software PDF SDK
Returns the handle of window corresponding to the specified document object and that can be used as parent for new dialog displaying.
HRESULT GetDlgParentWindow([in] IPXC_Document* pRDoc, [out, retval] HANDLE_T* nWindow);
- [in] The optional pointer to IPXC_Document. If you have a document - pass it here, and the function will return the handle of optimal window to be the parent of your dialog. You may pass the NULL value to get window handle of active document view or active main frame at least.
- [out, retval] Returns the handle to the optimal parent window.
Returns S_OK if operation was successful or error code in other cases.