Hi mnj70,
To extract a surface from a solid, change to the wireframe & surface workbench or the GSD1 workbench depending on what version of V5 you are using.
On the OPERATIONS toolbar or in the INSERT menu under OPERATIONS there are 2 extraction tools you can use.
The BOUNDARY function which will extract the boundary edge of a surface or
the EXTRACT function which will let you extract the face of a solid or the edge of a solid or surface.
First you can EXTRACT the face of the solid, then extract an edge of the face you created by using the same command or you can use the BOUNDARY function to extract the complete boundary edge of the face, your choice.
Hope this helps,
cheers,
JAKEY