Imports System.Text.RegularExpressions
Module Module1
  Sub Main()
    Dim sourcestring as String = "dfg  kld  hfgk    8:4  //sfga  sgasg  "
    Dim re As Regex = New Regex("\d:\d")
    Dim mc as MatchCollection = re.Matches(sourcestring)
    Console.WriteLine(mc(0).Groups(0).Value)
  End Sub
End Module