I keep getting standard SW error that data loaded is not STEP. The file is a .STP does solidworks have a different way of determining  STP to STEP

I only want error to show if part loaded is not a STP file

Set swApp = Application.SldWorks

    Path = BrowseFolder()

    If Path = "" Then

    MsgBox "Please select the path and try again"

    End

    Else

    Path = Path & "\"

    End If

    sFileName = Dir(Path & "*.STP") ' Change file extension here

    Do Until sFileName = ""

    Set FileTyp = swApp.LoadFile4(Path & sFileName, "r", swImportData, nErrors)

    Set FileTyp = swApp.ActiveDoc