Get only numbers from string

you can use Regex for this

Imports System.Text.RegularExpressions

then on some part of your code

Dim x As String = "123a123&*^*&^*&^*&^   a sdsdfsdf"
MsgBox(Integer.Parse(Regex.Replace(x, "[^\d]", "")))

try this:

Dim mytext As String = "123a123"
Dim myChars() As Char = mytext.ToCharArray()
For Each ch As Char In myChars
     If Char.IsDigit(ch) Then
          MessageBox.Show(ch)
     End If
Next

or:

Private Shared Function Num(ByVal value As String) As Integer
    Dim returnVal As String = String.Empty
    Dim collection As MatchCollection = Regex.Matches(value, "\d+")
    For Each m As Match In collection
        returnVal += m.ToString()
    Next
    Return Convert.ToInt32(returnVal)
End Function

Or you can use the fact that a String is an Array of Chars.

Public Function getNumeric(value As String) As String
    Dim output As StringBuilder = New StringBuilder
    For i = 0 To value.Length - 1
        If IsNumeric(value(i)) Then
            output.Append(value(i))
        End If
    Next
    Return output.ToString()
End Function