oPath_and_FileName = ThisDoc.PathAndFileName(False) ' without extension

oQuestion = MessageBox.Show("Do you want to derive this file?", "iLogic",MessageBoxButtons.YesNo)
If oQuestion = vbNo Then
Return
Else

' Create a new part file to derive the selected part into 
'note: kPartDocumentObject is the default template
Dim oPartDoc As PartDocument
oPartDoc = ThisApplication.Documents.Add(kPartDocumentObject, ThisApplication.FileManager.GetTemplateFile(kPartDocumentObject)) 

'Create a derived definition for the selected part
Dim oDerivedPartDef As DerivedPartUniformScaleDef

oDerivedPartDef = oPartDoc.ComponentDefinition.ReferenceComponents.DerivedPartComponents.CreateUniformScaleDef(ThisDoc.PathAndFileName(True))

' set the scale to use
oDerivedPartDef.ScaleFactor = 1

'define the mirror plane
'kDerivedPartMirrorPlaneXY = 27393 
'kDerivedPartMirrorPlaneYZ = 27394 
'kDerivedPartMirrorPlaneXZ = 27395 
oDerivedPartDef.MirrorPlane = 27394 

' Create the derived part.
oPartDoc.ComponentDefinition.ReferenceComponents.DerivedPartComponents.Add(oDerivedPartDef)

' Save the new derived part.
oPartDoc.SaveAs(oPath_and_FileName & "_derived.ipt", False)
oPartDoc.Close
MessageBox.Show("New file created at:" & vbLf & oPath_and_FileName & "_derived.ipt", "iLogic")

End If