I am not sure if I understood your problem.
From what I can understand, you are able to run bparchive from the crontab but when you type that command, job does not appear in the activity monitor.
Is that true?
If this is the case, then I dont see a reason why the job shouldn't appear in the activity monitor.
For logs, The bparchive logs are located at /usr/openv/netbackup/logs/bparchive.
Here is the command syntax:
bparchive [-p policy] [-s schedule][-L progress_log [-en]] [-S master_server[,master_server,...]] [-t policy_type] [-w [hh:mm:ss]] [-help] [-k "keyword_phrase"] -f listfile | filename