I simply export all my "run/debug configurations"
from the original project by:
copying the content of folder:
$My-Workspace\.metadata\.plugins\org.eclipse.debug.core\.launches
into a folder in the destination project (folder location or name doesn't matter, just as long as it is in the imported project)
and when I open eclipse to my workspace and the project - it will show up automatically in "run/debug configurations"
dialog (eclipse scan the projects for .launch files)
also after copying a .launch file into my project, i right click the root folder and choose refresh, wait for a minute and the configurations appear in the "run/debug configurations"