Trying to open Step file in VBA

[Eric Penfold]

Please help trying to open Step file with VBA. The code below won`t work says error 438??

Set swApp = Application.SldWorks

Private Sub Open_DrNo_Step_Click()

    Dim SourcePath As String
    Dim SubPath As String
    Dim Step As String
    Dim MyPath As String
    Dim StepName As String
    Dim StepFile As String
    Dim swApp As SldWorks.SldWorks
    Dim Doc As SldWorks.ModelDoc2
    Dim swFilter As String
    Dim swModel As ModelDoc2
    Dim swDocSpecification As DocumentSpecification
    Dim Cmbdata
    Dim FileError As Long
    Dim FileWarning As Long
    
    Set swApp = Application.SldWorks
    swApp.Visible = True

        Cmbdata = Split(Me.OpenDrawing.Value, "-")
        Cmbdata(0) = Replace(Cmbdata(0), "-", "")
      
    If ActiveSheet.Name = "Frost Drains" Then
            SourcePath = "\\DF-AZ-FILE01\Company\R&D\Drawing Nos\Frost Grates"
            SubPath = Me.OpenDrawing.Value
            
            GoTo OpenStep
            Else: SourcePath = "S:\R&D\Drawing Nos"
    End If
        
    If Val(Cmbdata(0)) >= 10001 And Val(Cmbdata(0)) <= 10050 Then
        SubPath = "10001-10050"
    ElseIf Val(Cmbdata(0)) >= 10051 And Val(Cmbdata(0)) <= 10100 Then
        SubPath = "10051-10100"
    ElseIf Val(Cmbdata(0)) >= 10101 And Val(Cmbdata(0)) <= 10150 Then
        SubPath = "10101-10150"
    ElseIf Val(Cmbdata(0)) >= 10151 And Val(Cmbdata(0)) <= 10200 Then
        SubPath = "10151-10200"
    End If
       
OpenStep:

        Step = Me.OpenDrawing.Value
        StepFile = SourcePath & "\" & SubPath & "\" & Step & ".Step"
        Set Doc = swApp.OpenDoc6(StepFile, swDocStep, swOpenDocOptions_Silent, "", FileError, FileWarning)

End Sub