What is the purpose of
B32Stinrg.Replace(":32B:", "")
?
With that set aside, your "GetNumbersfromStringUsingSB" method just needs a few tweeks. First off I changed it to return a Decimal instead of an Int64; i assumed you want that fraction component based on what you described. Second, I added condition to handle then case of "," or ".".
Function GetNumbersfromStringUsingSB(ByVal thestring As String) As Decimal
Dim sb As New System.Text.StringBuilder(thestring.Length)
For Each ch As Char In thestring
If Char.IsDigit(ch) Then
sb.Append(ch)
ElseIf ch = "."c OrElse ch = ","c Then
sb.Append("."c)
End If
Next
Return Decimal.Parse(sb.ToString)
End Function