A better Case (was "Create Loop with Case statement")

In the code below I am having trouble creating a loop to check the contents of TextBox1 as it can have upwards of 8 characters. This case statement works fine as long as the character count is one.
How do I count how many characters are in Textbox1 and then loop thru them? Am I on the right thought track?

'Bunch of other code here (Similar to below except using other fonts)
            sTbItem1 = TextBox1.Value
            Select Case sTbItem1
                Case "."
                    sTbItem1 = Replace(sTbItem1, ".", "ù")
                Case "1"
                    sTbItem1 = Replace(sTbItem1, "1", "ï")
                Case "2"
                    sTbItem1 = Replace(sTbItem1, "2", "ð")
                Case "3"
                    sTbItem1 = Replace(sTbItem1, "3", "ñ")
                Case "4"
                    sTbItem1 = Replace(sTbItem1, "4", "ò")
                Case "5"
                    sTbItem1 = Replace(sTbItem1, "5", "ó")
                Case "6"
                    sTbItem1 = Replace(sTbItem1, "6", "ô")
                Case "7"
                    sTbItem1 = Replace(sTbItem1, "7", "õ")
                Case "8"
                    sTbItem1 = Replace(sTbItem1, "8", "ö")
                Case "9"
                    sTbItem1 = Replace(sTbItem1, "9", "÷")
                Case "0"
                    sTbItem1 = Replace(sTbItem1, "0", "î")
            End Select
        End If
    End If
    sTolerance = sTbItem1
    TextBox1.Text = sTbItem1
End If

Any hints, tips or examples are appreciated.

I dont follow, Partial match?

Ok, I understand that now.
I will see how I can apply that in a TextBox.
Hmm, does it matter if the all of this is in a userform?

like this perhaps.

Function ReplaceCharacters(Text As String, OldText As String, NewText As String) As String

    Dim lngIndex As Long
    
    If Len(OldText) = Len(NewText) Then
        For lngIndex = 1 To Len(OldText)
            Text = Replace(Text, Mid(OldText, lngIndex, 1), Mid(NewText, lngIndex, 1))
        Next
    End If
    ReplaceCharacters = Text

End Function

Private Sub CommandButton1_Click()

    TextBox1.Text = ReplaceCharacters(TextBox1.Text, ".1234567890", "ùïðñòóôõö÷î")
    
End Sub

Oh sure, now see what you did!?
Now I have to edit some umpteen pages and condense them to about 1 page.
Thanks a lot!



Thanks to all.