Inserts a group into the list view control.
LRESULT InsertGroup(
   int index,
   PLVGROUP pgrp 
);
Parameters
- index 
 The index of the item where the group is to be inserted.
- pgrp 
 A pointer to an LVGROUP structure containing the group to be added.
Return Value
Returns the index of the item that the group was added to, or -1 if the operation failed.
Remarks
This member function emulates the functionality of the LVM_INSERTGROUP message, as described in the Windows SDK.
Requirements
Header: afxcmn.h