Function GetDigit(v)
  Dim re
  Set re = CreateObject("VBScript.RegExp"): re.Pattern = "\d+"
  If re.test(v) Then GetDigit = Val(re.Execute(v)(0))
End Function

Function iDigit(cell$)
 With CreateObject("VBScript.RegExp")
     .Global = True
     .Pattern = "\/(\d+)\/"
   If .test(cell) Then
       iDigit = CDbl(.Execute(cell)(0).SubMatches(0))
   Else
     iDigit = ""
   End If
 End With
End Function

Sub Macro1()
Dim LastRow As Long, i As Long
    LastRow = Cells(Rows.Count, 1).End(xlUp).Row
    For i = 2 To LastRow
        Cells(i, 3) = Split(Split(Cells(i, 1), "catalog/")(1), "/")(0)
    Next
End Sub