A sheet in Excel can be hidden using the vbscript below.
Set objXLApp = CreateObject("Excel.Application")
objXLApp.Visible = false
Set objXLWb = objXLApp.Workbooks.Open("C:\Robusta_Project\xxx\xyz.xlsx")
Set oSheet = objXLWb.Worksheets("Summary")
oSheet.Visible = xlSheetHidden
objXLWb.save
objXLWb.close false
objXLApp.Quit
Set objXLWb = nothing
Set objXLApp = nothing