Here is a usage example:
include \masm32\include\masm32rt.inc
include Showerror.inc
includelib Showerror.lib
.data
title$ db "This is Yves's macro:", 0
.code
start:
invoke SetLastError, 33
MsgBox 0, LastError$(), "Hello, this is a Masm32 macro:", MB_OK or MB_ICONERROR or MB_SETFOREGROUND
invoke GetLastErrorMsg, addr title$
exit
end start