Yes, but DLO is a totally different console, and a different software. You are seeing and backing up the share from Backup Exec console. Please note that DLO and Backup Exec are different softwares. So, you have installed DLO, but if backing up the shares is all you need, do not use DLO for that. You dont need DLO, basically. So, no license required, go ahead backup shares and there should be no problem. It is just that if you have remote agent software installed on the target box, it makes your backup performance better. So, even for share backup, i would recommend installing a remote agent software to the Windows XP box, but no license required.
Regarding the DLO question, yes you are licensed for 5 users, but DLO configuration is done through a separate console and is a totally different type of solution, used for backup of desktops and laptops and really nothing to do with backup of shares.
Thanks