Pattern matching in a textbox

Question

I am trying to accomplish the following:

Read the contents of a textbox and look for a pattern match, then execute a series of events when (or if) that pattern is found.

That much I have accomplished, but how do I get the program to look for other instances of that pattern within the same textbox.

For instance, suppose the program finds a match at index 0 in the textbox, then executes its series of events. How do I get a recursion

of the text while ignoring the text section previously covered.

Imports SpeechLib

Imports System.Text.RegularExpressions

Public Class Form1

    Dim compVoice As New SpVoice

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles Me.Load

        Dim regex As Regex = New Regex("^\d\d:\d\d")

        Dim td As DateTime = DateTime.Now()

        If CInt(TextBox1.Text) = td.Day Then

            'run textbox1 here.

            If regex.IsMatch(txtDay1.Text, 0) Then

                compVoice.Volume = 100

                compVoice.Speak("Warning")

                compVoice.Volume = 50

                compVoice.Speak(txtDay1.Text.Substring(6))

            Else

                compVoice.Speak("No text present.")

            End If

        ElseIf CInt(TextBox2.Text) = td.Day Then

            'run textbox2 here

            If regex.IsMatch(txtDay2.Text, 0) Then

                compVoice.Volume = 100

                compVoice.Speak("Warning")

                compVoice.Volume = 50

                compVoice.Speak(txtDay2.Text.Substring(6))

            Else

                compVoice.Speak("No text present.")

            End If

        ElseIf CInt(TextBox3.Text) = td.Day Then

            If regex.IsMatch(txtDay3.Text, 0) Then

                compVoice.Volume = 100

                compVoice.Speak("Warning")

                compVoice.Volume = 50

                compVoice.Speak(txtDay3.Text.Substring(6))

            Else

                compVoice.Speak("No text present.")

            End If

        Else

            Exit Sub

        End If

    End Sub

End Class