Sub Main()
    Dim doc As Document = ThisDoc.Document
    SetTitle(doc)
End Sub
Private Sub SetTitle(doc As Document)
    Dim delka As String = GetParameterValue(doc, "DÉLKA")
    Dim prednazev As String = GetPropertyValue(doc, "PREDNAZEV")
    Dim typ As String = GetPropertyValue(doc, "TYP")
    doc.PropertySets("{F29F85E0-4FF9-1068-AB91-08002B27B3D9}")("Title").Value = String.Format("{0} {1}-{2}", prednazev, typ, delka)
End Sub
Private Function GetPropertyValue(doc As Document, propertyName As String) As String
    Dim userDefinedProperties As PropertySet = doc.PropertySets("{D5CDD505-2E9C-101B-9397-08002B2CF9AE}")
    Dim prop As Inventor.Property
    Try
        prop = userDefinedProperties(propertyName)
    Catch ex As Exception
        prop = userDefinedProperties.Add("", propertyName)
    End Try
    Return prop.Value.ToString()
End Function
Private Function GetParameterValue(doc As Document, paramName As String) As String
    Dim part As PartDocument = doc
    Dim userParameters As UserParameters = part.ComponentDefinition.Parameters.UserParameters
    Dim param As Parameter
    Try
        param = UserParameters(paramName)
    Catch ex As Exception
        userParameters.AddByValue(paramName, 0, "mm")
    End Try
    'Nastavit propisovani parametru do iVlastnosti
    param.ExposedAsProperty = True
    Dim value As Double = param.ModelValue * 10
    Return String.Format("{0} mm", value)
End Function

Sub Main()
    Dim doc As Document = ThisDoc.Document
    SetTitleAsExpression(doc)
End Sub
Private Sub SetTitleAsExpression(doc As Document)
    Dim delka As String = GetParameterValue(doc, "DÉLKA")
    Dim prednazev As String = GetPropertyValue(doc, "PREDNAZEV")
    Dim typ As String = GetPropertyValue(doc, "TYP")
   doc.PropertySets("{F29F85E0-4FF9-1068-AB91-08002B27B3D9}")("Title").Expression = "=<PREDNAZEV> <TYP>-<DÉLKA>"
End Sub