Simple join lineCurvelist

I can't quite figure out why this won't work. I get an error on the last line. It seems that I can not cast a lineCurve as a curve. NOt sure how to make a line into a curve.

Thanks for the help

Private Sub RunScript(ByVal x As List(Of Line), ByVal y As Object, ByRef A As Object, ByRef B As Object)
'------Convert Lines to LineCurves--------------'
'------Convert Lines to LineCurves--------------'
Dim i As Integer
Dim lineList As New List(Of Line)
Dim lineCont As New Line
Dim myLineCurveList As New List(Of LineCurve)

For i = 0 To x.Count - 1

lineCont = x(i)
lineList.Add(lineCont)
Next

For Each lineCont In lineLIst
Dim myLineCurve As New LineCurve(lineCont)

myLineCurveList.Add(myLineCurve)

Next
'------End Convert Lines to LineCurves--------------'
'------End Convert Lines to LineCurves--------------'


A = LineCurve.JoinCurves(myLineCurveList)



End Sub