They could just type the full path to the script?
Or, you could always ask (nicely) an Admin to add the path in
/etc/profile,
/etc/environment, or some such. But that might fall on deaf ears.
Would it really kill them just to add either the path, or an alias to the script, in their .profile?
edit: or a sysadmin-created sym-link in some public bin directory (I forgot to mention), as cabrao says