How to add exception handling

I just learned about exception handling. So, I am still getting use to it. I know how to do the basic exception handling like entering in a correct value for division and having it throw a DividebyZeroException if a incorrect value is entered.

But I need help some help on doing the following:

Create an exception handling to throw an error if:

1) The number of integer in each row are not equal to each other for example: Matrix = [ 3 4; 9 8 1] should be: matrix = [ 3 4 2; 9 8 1]

2) the semicolon ";" that I use as a separator is replace by an invalid character such as: matrix = [ 3 4 2 # 9 8 1]

3) The starting character of the matrix is not '[' or the ending character is not ']': for example A = ] 1 2 3[ should be A = [1 2 3]

This is my code:

This is from my "main" in which I create the string. The string is called into the method in the class "Matrix".

string text = "A = [8 5 5 4; 2 6 5 3; 8 5 2 6]";

this is my class

public string[,] Matrix(string text)
{

        char[] splitOne = { '[', ']' };
        char[] splitTwo = { ';' };
        char[] splitThree = { ' ' };
        words = text.Split(splitOne)[1]
                               .Split(splitTwo, StringSplitOptions.RemoveEmptyEntries)
                               .Select(x => x.Split(splitThree, StringSplitOptions.RemoveEmptyEntries))
                               .ToArray();

            if (!text.Contains(";"))
            {
                Console.WriteLine("malformed seperator");
                return null;
            }

            if (text.Split(';')[0].Replace(" ", "").Length != text.Split(';')[1].Replace(" ", "").Length)
            {
                Console.WriteLine("unbalanced matrix");
                return null;
            }

    string[,] matrix = new string[words.Length, words[0].Length];
    for (int i = 0; i < words.Length; ++i)
    {
        for (int j = 0; j < words[i].Length; ++j)
        {
            matrix[i, j] = words[i][j];
        }
    }

    for (int i = 0; i < matrix.GetLength(0); i++)
    {
        for (int j = 0; j < matrix.GetLength(1); j++)
        {
            Console.Write("{0} ", matrix[i, j]);
        }
        Console.WriteLine();
    }
    return matrix;
}

How would I make these exceptions work. Right now, the separator works fine. But I can't get this part to work:

1) The number of integer in each row are not equal to each other for example: Matrix = [ 3 4; 9 8 1] should be: matrix = [ 3 4 2; 9 8 1]

it keeps showing my error message even when the matrix is balance.

I also need help on:

3) The starting character of the matrix is not '[' or the ending character is not ']': for example A = ] 1 2 3[ should be A = [1 2 3]