Hi c3g, yes to add buttons there you will need to edit SidePane.htm, and locate the section for "SubDTabContent" which looks like this:

                    <div id="SubDTabContent">
					    <table style="width:100%">
						    <tr>
								<td><moi:CommandMenuButton icon="icons/SubDCreateIcon.png" menu="SubDCreateMenu.htm"><moi:Text textid="SubD create menu button"/></moi:CommandMenuButton></td>
								<td><moi:CommandButton style="visibility:hidden;">&nbsp;</moi:CommandButton></td>
								<td><moi:CommandButton style="visibility:hidden;">&nbsp;</moi:CommandButton></td>
								<td><moi:CommandButton style="visibility:hidden;">&nbsp;</moi:CommandButton></td>
				 		    </tr>
					    </table>
                    </div>

Edit it to be like this and place 64x64 pixel image files "STEPIn.png" and "STEPOut.png" inside the ui\icons folder:

					<div id="SubDTabContent">
						<table style="width:100%">
							<tr>
								<td><moi:CommandMenuButton icon="icons/SubDCreateIcon.png" menu="SubDCreateMenu.htm"><moi:Text textid="SubD create menu button" /></moi:CommandMenuButton></td>
								<td><moi:CommandButton icon="icons/STEPIn.png" onclick="moi.geometryDatabase.open('e:\\test.step');">STEP In</moi:CommandButton></td>
								<td><moi:CommandButton icon="icons/STEPOut.png" onclick="moi.geometryDatabase.saveAs('e:\\test.step');">STEP Out</moi:CommandButton></td>
								<td><moi:CommandButton style="visibility:hidden;">&nbsp;</moi:CommandButton></td>
							</tr>
						</table>
					</div>

- Michael

Hi, Michael
Thank you very much. According to your guidance, I have successfully made the icon. I believe the moi 3d forum is definitely a place full of love, the people here are very warm and friendly, it is a great honor to meet you here.