While using 3.3.8, this worked fine:
Local $fFile = "C:\Users\" & @UserName & "\Documents\test.xlsx"
If Not FileExists($fFile) Then
MsgBox(0, "Excel File Test", "Can't run this script b/c you don't have " & @CRLF & $fFile & " open")
Exit
EndIf
$oExcel = ObjGet("", "Excel.Application") ;Gets an existing Excel Object
If @error Then ;Error traps if Excel file is not open
MsgBox(0, "ExcelFileTest", "You don't have Excel running at this moment. Error code: " & Hex(@err