The following VBA example links frames of paragraph text, displaying the index number of the frame following the first frame.
Sub Test()
Dim s As Shape
Dim s1 As Shape
Dim s2 As Shape
Dim t As Text
Dim f As TextFrame
Dim d As Document
Set d = CreateDocument
Set s = d.ActiveLayer.CreateParagraphText(2, 2, 5, 5, String$(750, "Z"))
Set s1 = d.ActiveLayer.CreateParagraphText(5, 5, 8, 8)
Set s2 = d.ActiveLayer.CreateParagraphText(8, 8, 10, 10)
Set t = s.Text
' Link the frames together.
t.Frame.LinkTo s1
s1.Text.Frame.LinkTo s2
' Get the first frame.
Set f = t.Frames(1)
MsgBox "The index number of the next frame is: " & f.Next.Index
End Sub