Impleading parties and supplementary proceedings are truly beyond your ability pro se to handle. I would recommend you speak with an attorney. I am in Miami and would be happy to review your documentation. Is the defendant viable? No specific return of the execution is needed anymore, you can simply allege that reality if you dont have any assets you know about. You need to do discovery from the defendant to determine if there are any assets.
The answers given are limited to the facts as given and presumed by the answer itself. Without seeing actual written documentation or having a conference to more fully explore the issues, this short answer has only limited application. Make sure to seek legal counsel and provide all documentation to get assistance in making informed legal choices. Bstein@dcfsz.com, 305 377 1505