parsing a sentence(help please)

As you haven't stated what your requirements really are, given the problem description you've shown you could simply replace the comma with and in a straightforward text replacement. For instance (and I'm assuming C# here since you haven't even said which language:

string text = "V1,V2";
Console.WriteLine(string.Replace(",", " and ");

You really need to say what your requirements really are before you'll get much better as an answer.