>I want to click a buttom to lunch Excel with a excel document which a get from getfile().

In the click event of the button:

lcFilename = GETFILE()

IF !EMPTY( lcFileName )
oShell = CREATEOBJECT( "Shell.Application" )

oShell.Open( lcFilename )
ENDIF

This uses the Windows Script Host (WSH), which has become a hot topic on the UT. If you have any questions about it, do a search for WSH.