There should be no problem with using a regular remote agent software. It will be a file level backup which you can do like any other regular windows machine. So, all you need is install remote agent software on the hyper-v server and in Backup Exec selection list, include that server and the vhd files there in backup. Make sure to turn on AOFO in the backup job properties for protecting these files. This will be a regular file level backup and restore. Please note that in order to perform this operation from another Backup Exec server, you may need to purchase a remote agnet license. Also, you will not be getting the features that are available in Hyper-V agent, which can perform online backup and consistent restore. So, definitely Hyper-V agent will be recommended, but from short term perspective, regular file level backup can be used. Make sure to test a backup and restore.
Please mark it a solution, if this is useful.
Thanks