MSGWrap.lParam Property (Visio)
Gets or sets the lParam member of the MSG structure being wrapped. Read/write.
expression A variable that represents a MSGWrap object.
The lParam property corresponds to the lParam member of the MSG structure defined as part of the Microsoft Windows operating system. If an event handler is handling the OnKeystrokeMessageForAddon event, Microsoft Visio passes a MSGWrap object as an argument when this event fires. A MSGWrap object is a wrapper around the Windows MSG structure.
For details, search for "MSG structure" on MSDN, the Microsoft Developer Network.