In reply to nivas:
There are several ways of getting the name of the test string passed in with +UVM_TESTNAME, including uvm_cmdline_proc.get_arg_value(), then you can proceed as above.
Note that you should not have to do this as any tool following the UCIS standard for collecting coverage data has mechanisms for mapping requirements to many different types of coverage metrics. Mapping a requirement to the passing of a test is one of them.