This is a little confusing since they do not explicitly name it RAID10 but what you need to do is to create a virtual disk with the RAID1 profile and assign more than two disks, it will accept 4 or more and make it a RAID 10.
You may not be able to configure 48 drives in a Vdisk. If you do not provide us with the array model (ie: 2540, 6140, 6180, 6540, etc...) you have and its firmware level, we will not be in position to tell you if 48 drives will work or not.
A spare drive is not dedicated to a vdisk, it is global to the array. A guideline for the spare is to have 1 hot spare for every 30 drives (per drive type). For example, if a storage array contains 20 SATA drives and 60 FC drives, there should be a minimum of 1 SATA hot spare and 2 FC hot spares. As far as I know, you can have only 6 or 7 drives in a Vdisk for the 2500-M2 and for RAID 0 or 1, and a maximum of 30 drives in a Vdisk for all the other RAID levels.
One drive can only be in one Vdisk at a time.
With these information, you should be able to configure the array as your needs.