The first thing you have to do is to download the cod and jad file provided by the 3rd party application. Then after you are done with coding and packaging the application. You have to copy cod & jad files of your application and 3rd party application to the same folder.
Configure the path variable (environment variables) to include the tool updatejad.exe, this will be usually under c:\program files\Research In Motion\BlackBerry JDE
Open command prompt, navigate to the folder where you have copied the application cod files and jad files, then execute the following command
updatejad -q -n [your_application_name.jad] [space] [3rd_party_application_name.jad]
The usage of updatejad tool is as follows.
Usage: updatejad.exe -q -n [input.jad] [[additional.jad] ...]
-q Quiet mode
-n No backup file
More than one additional.jad may be specified.