If the command name has a .JAR extension and JARPATH is set (the same syntax as PATH - path1;path2;path3) TCC will search it looking for a matching filename. If found, the command line will be reformatted (inserting "java.exe -jar" at the beginning) and executed. For example:
myjar.jar 1 2 3
will be executed as:
java.exe -jar myjar.jar 1 2 3