how to chnage font of a selected word of a Word File

Word.Range r = WordDoc.Range(ref onewstart, ref onewe);    
            //object rText = true;
            find = r.Find;
            find.Text = "Rest";
            r.Find.Font.Underline = Word.WdUnderline.wdUnderlineSingle;
            r.Find.Font.Bold = 1;
            find.Execute(ref oMissing, ref matchword, ref matchwholeword, ref matchwildcards, ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing, ref oMissing);
            if (find.Found)
            {
                Word.Table oTable;
                Word.Range newrng;
                int i = r.Start;
                object o = r.Start;
                object e = r.End;
                newrng = WordDoc.Range(ref o, ref e);
                string te = newrng.Text;
                oTable = WordDoc.Tables.Add(newrng, 1, 1, ref oMissing, ref oMissing);
                oTable.Columns.Item(1).Cells.Item(1).Range.Text = te;
                oTable.Rows.Item(1).Range.Bold = 1;
                oTable.Borders.OutsideLineStyle = Word.WdLineStyle.wdLineStyleNone;
                oTable.Cell(1, 1).Shading.BackgroundPatternColor = Word.WdColor.wdColorGray10;
                //  Word.Range newr;
                object os = oTable.Range.End;
                object oe = oTable.Range.End + 1;
                WordDoc.Range(ref os, ref oe).Font.Size = 2;
            }