As you suggested the issue is the % signs.
Add another % -sign after both of them and it should be fixed. % -> %%
Here is your script that should work:
Set SapGuiAuto = GetObject("SAPGUI")
Set application = SapGuiAuto.GetScriptingEngine
End If
If Not IsObject(connection) Then
Set connection = application.Children(0)
End If
If Not IsObject(session) Then
Set session = connection.Children(0)
End If
If IsObject(WScript) Then
WScript.ConnectObject session, "on"
WScript.ConnectObject application, "on"
End If
session.findById("wnd[0]").maximize
session.findById("wnd[0]/tbar[0]/okcd").text = "/nsuim"
session.findById("wnd[0]").sendVKey 0
session.findById("wnd[0]/usr/cntlTREE_CONTROL_CONTAINER/shellcont/shell").expandNode "02 1 2"
session.findById("wnd[0]/usr/cntlTREE_CONTROL_CONTAINER/shellcont/shell").topNode = "01 1 1"
session.findById("wnd[0]/usr/cntlTREE_CONTROL_CONTAINER/shellcont/shell").expandNode "03 2 7"
session.findById("wnd[0]/usr/cntlTREE_CONTROL_CONTAINER/shellcont/shell").selectItem "04 2 8","1"
session.findById("wnd[0]/usr/cntlTREE_CONTROL_CONTAINER/shellcont/shell").ensureVisibleHorizontalItem "04 2 8","1"
session.findById("wnd[0]/usr/cntlTREE_CONTROL_CONTAINER/shellcont/shell").topNode = "01 1 1"
session.findById("wnd[0]/usr/cntlTREE_CONTROL_CONTAINER/shellcont/shell").clickLink "04 2 8","1"
session.findById("wnd[0]/usr/tabsTABSTRIP_TAB/tabpTAB1/ssub%%_SUBSCREEN_TAB:RSUSR002:1001/radLOCK").select
session.findById("wnd[0]/usr/tabsTABSTRIP_TAB/tabpTAB1/ssub%%_SUBSCREEN_TAB:RSUSR002:1001/radLOCK").setFocus
session.findById("wnd[0]/tbar[1]/btn[8]").press
session.findById("wnd[0]/mbar/menu[0]/menu[3]/menu[1]").select
session.findById("wnd[1]/usr/ctxtDY_PATH").text = "C:\temp"
session.findById("wnd[1]/usr/ctxtDY_FILENAME").text = "Export.XLSX"
session.findById("wnd[1]/usr/ctxtDY_FILENAME").caretPosition = 22
session.findById("wnd[1]/tbar[0]/btn[11]").press
session.findById("wnd[0]/tbar[0]/btn[15]").press
session.findById("wnd[0]/tbar[0]/btn[15]").press
session.findById("wnd[0]/tbar[0]/btn[15]").press
