When text in textbox starts with , then

Hello,

Refer the code given below. Its working great as per your Requirement.

Public Class Form2
    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        Dim YourString As String = TextBox1.Text
        TextBox2.Text = YourString.Substring(0, 4) 'Extracting First Four characters to check
        Dim d As String
        d = TextBox2.Text
        If IsNumeric(d) = True Then 'Checking whether first four characters are Numeric value or not
            TextBox3.Text = TextBox1.Text 'Display the Result
        Else
            TextBox3.Text = YourString.Remove(0, 4)
        End If
    End Sub
End Class