Convert HTML Tables To DataSet In C#

private DataSet ConvertHTMLTablesToDataSet(string HTML) {
    // Declarations
    DataSet ds = new DataSet();
    DataTable dt = null;
    DataRow dr = null;
    DataColumn dc = null;
    string TableExpression = "<TABLE[^>]*>(.*?)</TABLE>";
    string HeaderExpression = "<TH[^>]*>(.*?)</TH>";
    string RowExpression = "<TR[^>]*>(.*?)</TR>";
    string ColumnExpression = "<TD[^>]*>(.*?)</TD>";
    bool HeadersExist = false;
    int iCurrentColumn = 0;
    int iCurrentRow = 0;
    // Get a match for all the tables in the HTML
    MatchCollection Tables = Regex.Matches(HTML, TableExpression, RegexOptions.Multiline | RegexOptions.Singleline | RegexOptions.IgnoreCase);
    // Loop through each table element
    foreach(Match Table in Tables) {
        // Reset the current row counter and the header flag
        iCurrentRow = 0;
        HeadersExist = false;
        // Add a new table to the DataSet
        dt = new DataTable();
        //Create the relevant amount of columns for this table (use the headers if they exist, otherwise use default names)
        // if (Table.Value.Contains("<th"))
        if (Table.Value.Contains("<TH")) {
            // Set the HeadersExist flag
            HeadersExist = true;
            // Get a match for all the rows in the table
            MatchCollection Headers = Regex.Matches(Table.Value, HeaderExpression, RegexOptions.Multiline | RegexOptions.Singleline | RegexOptions.IgnoreCase);
            // Loop through each header element
            foreach(Match Header in Headers) {
                dt.Columns.Add(Header.Groups[1].ToString());
            }
        } else {
            for (int iColumns = 1; iColumns <= Regex.Matches(Regex.Matches(Regex.Matches(Table.Value, TableExpression, RegexOptions.Multiline | RegexOptions.Singleline | RegexOptions.IgnoreCase)[0].ToString(), RowExpression, RegexOptions.Multiline | RegexOptions.Singleline | RegexOptions.IgnoreCase)[0].ToString(), ColumnExpression, RegexOptions.Multiline | RegexOptions.Singleline | RegexOptions.IgnoreCase).Count; iColumns++) {
                dt.Columns.Add("Column " + iColumns);
            }
        }
        //Get a match for all the rows in the table
        MatchCollection Rows = Regex.Matches(Table.Value, RowExpression, RegexOptions.Multiline | RegexOptions.Singleline | RegexOptions.IgnoreCase);
        // Loop through each row element
        foreach(Match Row in Rows) {
                // Only loop through the row if it isn't a header row
                if (!(iCurrentRow == 0 && HeadersExist)) {
                    // Create a new row and reset the current column counter
                    dr = dt.NewRow();
                    iCurrentColumn = 0;
                    // Get a match for all the columns in the row
                    MatchCollection Columns = Regex.Matches(Row.Value, ColumnExpression, RegexOptions.Multiline | RegexOptions.Singleline | RegexOptions.IgnoreCase);
                    // Loop through each column element
                    foreach(Match Column in Columns) {
                            // Add the value to the DataRow
                            dr[iCurrentColumn] = Column.Groups[1].ToString();
                            // Increase the current column
                            iCurrentColumn++;
                        }
                        // Add the DataRow to the DataTable
                    dt.Rows.Add(dr);
                }
                // Increase the current row counter
                iCurrentRow++;
            }
            // Add the DataTable to the DataSet
        ds.Tables.Add(dt);
    }
    return ds;
}