Performing a procedure for each form edit
It looks to me that you could use a method that returns the appropriate string.  Something like the following, which follows the pattern in your code:

static string GetEdit(string txt)
{
    string rgxExpr = @"(\w+)\s([\w\s]*)"; // Pega primeiro nome
    string rgxExpr2 = @"\b(\w{1})"; // Abreviação    
    Match match1 = Regex.Match(txt, rgxExpr);
    Match match2 = Regex.Match(match1.Groups[1].ToString(), rgxExpr2);
    return match1.Groups[2].ToString().ToUpper() + ", " + match2.Groups[1].ToString().ToUpper();
}


You could do something similar with the other duplicated code by using a list of strings that correspond to a list of textboxes. allowing you to add or delete as needed.