Kinda forgot that you'd replied, I'm sorry!
When you receive the WM_NOTIFY message, the lParam is important: it contains an
NMHDR structure. You can access this structure using
RtlMoveMemory() in Kernel32.dll as follows:
JScript code:
var NMHDR = Interop.Allocate(52);
Interop.Call("Kernel32.dll","RtlMoveMemory",NMHDR.DataPtr,lParam,52);
Reading byte 8 from the NMHDR structure, you should be able to filter the LVN_ENDLABELEDITW value. You should then perform the actions I described above.