command line

There is no easy built in way in TestComplete on the command line to say "Use this value in the parameter for this test" or anything like that.

There are ways of doing so, however.  One way is, if you go to https://github.com/smartbear-testcomplete/ogre-utilities/tree/master/Releases/Latest and download the tcx file, this is a script extension bundle that I developed for various utilities and such.  It has a method called getTCCommandLineParameter. Pass in to that method the parameter name you want to parse out, and it will retrieve that for use in your project.

Another way that I've used in the past is that, instead of passing in parameters in the commandline, I've created a config file (an INI type text file) that resides in the folder with my project.  The first thing that my project does, then, is read that INI file and update Project variables (Project.Variables) with the appropriate values from that INI.  If I want to change the values for some reason, I simply update the INI.

These are just two ways of doing it... I'm sure there are others.

This is all in TestComplete.  All Jenkins does is execute the command line.  Everything I indicated are code alterations you'll need to make to your TestComplete project to accommodate "custom" parameterization.