RIchTextBox How To Eliminate All Non_ascii chars

[TechNix]

The character you are pertaining is an "En Dash" like this "–"?
or an "Em Dash" which is longer than the "En Dash"?
the Ascii value for an En Dash is 150 while the Em Dash is 151.
Anyways, assuming its an Em Dash, the following code will replace all the Em Dash to Space in the RTB control:

Private Sub Command1_Click()
RichTextBox1.Text = RemoveEmDash(RichTextBox1.Text)
End Sub

Function RemoveEmDash(str As String) As String
RemoveInvalid = Replace(str, Chr$(151), " ")
End Function