Dim Suchwort As String = "irgendwas"
Dim text() As String = {"irgendwas=xyz"}
Dim Wert As String = ""
 
For i As Integer = 0 To text.Length - 1
   If text(i).StartsWith(Suchwort) AndAlso _
      text(i).Length > Suchwort.Length + 1 Then
 
      Wert = text(i).Substring(Suchwort.Length + 1)
      'wert verarbeiten
   End If
Next i

For i As Integer = 0 To text.Length - 1
   With text(i)
      If .StartsWith(Suchwort) AndAlso _
         .Length > Suchwort.Length + 1 Then
 
         Wert = .Substring(Suchwort.Length + 1)
         'Wert weiter verarbeiten
      End If
   End With
Next i