CST in batch mode opens GUI

I am running the following line

"C:\Program Files (x86)\CST STUDIO SUITE 2016\CST DESIGN ENVIRONMENT.exe" -m C:\Temp\macro.bas

where

macro.bas

is

Sub Main
OpenFile("C:\Temp\Downloads.cst")
StoreParameter "offset", 1
Rebuild()
Solver.Start
End Sub

CST opens a GUI while running the above. Is there a switch for the command line that suppresses the GUI?

I could not see any in the command line options.