Replacing the string in VB.NET

The String class has the Replace method like testString.Replace("..vblf",".vbLf");.

Similar method is available with StringBuilder class as well. If you are going to do many replacements then better use string builder class

as per your comment

here is the sample with regEx

private void button1_Click(object sender, EventArgs e)
 {
     string input = "bla bla bla ..-anycharacter-vbLf bla bla bla ..-test-vbLf ";
     string pattern = "..-[a-z]*-vbLf";
     string result1 = Regex.Replace(input, pattern, new MatchEvaluator(removeDot));
     MessageBox.Show(result1.ToString());

 }
 private static string removeDot(Match m)
 {
     string x = m.ToString().Replace("..", ".");
     return x;
 }

Extracting the match without the double dot.