To view the project properties:
Where appropriate, click
Show Advanced Directives,
, to view more options.
On the PL/I Link tab there is a field for libraries. This is used for both external libraries such as ODBC, and for linking projects. If you were working on a project that required a .lib that was created by a second project, you would put the name of that .lib here and if it is updated by the build process, this project would be re-linked.