You can use the $(TARGETNAME_OUTPUT_FILE) variable at every target's post build step, and maybe some other variable like $(PROJECT_DIR) to determine the target location (see the WiKi under "variable expansion" for a complete list of available variables). Then use the copy or cp command.
However, it's much easier to just change the output directories of all targets under "Project properties", so the libraries are created in the right location. No copying necessary.