次のサンプルコードは、TabStripInsertTabImageプロパティを設定します。
fpSpread1.Sheets.Count = 2;
fpSpread1.TabStripInsertTab = true;
fpSpread1.TabStripInsertTabImage = System.Drawing.Image.FromFile("C:\\SpreadWin7\\SpWin7CSharp\\fpicon.ico");
fpSpread1.Sheets.Count = 2
fpSpread1.TabStripInsertTab = True
fpSpread1.TabStripInsertTabImage = System.Drawing.Image.FromFile("C:\SpreadWin7\SpWin7CSharp\fpicon.ico")