The rubber stamp annotation object (ANNOBJECT_STAMP_XXX) is a stamp object that has a metafile. For more information about the stamp tool, refer to Stamp Tool.
In design mode, click on the object with the right mouse button to do the following:
Change the fixed properties. See Fixed Dialog Box for Annotations.
For each Rubber Stamp, there is a corresponding tool that can be set using LAnnAutomation::SetTool. The Rubber Stamp tools are ANNTOOL_STAMP_XXX.