It looks like you're missing the inclusion of the rxapi.lib library module.
Select Project menu->Settings. Pick the Link tab and the General category.
In the "Object/library modules" edit field add the missing library. I don't
know what sample you're compiling but if the arx lib directory is on MSVC++
path you can just add the name otherwise you can include an absolute path or
the relative path, i.e., ..\..\lib\rxapi.lib. As a rule you should probably
always include acad.lib, acedapi.lib, and rxapi.lib in this field. Other
libs will be needed depending on what functions you're using.
--
Tom Stoeckel
AutoCAD Express Tools Developer
tom.st...@autodesk.com
http://www.autodesk.com/expresstools