Option Explicit
 
Private Sub Command1_Click()
    Dim s1 As Long
    Dim e1 As Long
    Dim ende As Long
 
    s1 = 0
    ende = Len(rtf.Text)
 
    Do
        s1 = rtf.Find("~", s1, ende)
        If s1 = -1 Then Exit Do
        e1 = rtf.Find("~", s1 + 1, ende)
        If e1 = -1 Then Exit Do
        rtf.SelStart = s1 + 1
        rtf.SelLength = e1 - s1 - 1
'        Falls Tilde selbst mit markiert werden soll, dann so:
'        rtf.SelStart = s1
'        rtf.SelLength = e1 - s1 + 1
        rtf.SelColor = RGB(255, 0, 0)
        s1 = e1 + 1
    Loop Until s1 > ende
End Sub
 
Private Sub Form_Load()
    rtf.Text = "~ein auto ist was schönes~zzzzzz~ababababa~xxxxxxxxxx~mmmm~"
End Sub

Gru? Michi aus Hannover

1 + 1 = 3 f?r hinreichend gro?e 1