accidentally deleted USB entry from UEFI boot order list

hi,

i recently purchased a dell xps 13, though not the developer edition.  instead, since a refurbished machine with windows 8 pre-installed came on sale in the dell outlet, i went with that.  nevertheless, i am now trying to install ubuntu 13.04 (raring) on the machine without deleting windows 8 (so a dual boot).  despite difficulties that others have reported on various online forums in getting the ubuntu installer to see the windows partitions and/or to install ubuntu in UEFI mode rather legacy BIOS mode, i believe i can perform the installation successfully *if* i can get the BIOS (currently version A09) to allow me to add the USB port(s) to the boot order.

and herein lies my issue.

i believe i determined how to do that -- after accessing the BIOS, under the "boot" tab, there is an option under the UEFI boot list to "add a boot entry" or something like that.  when i selected that, a screen popped up offering me two choices of additional devices: one represented by a very long line tof text hat made reference to USB, and another represented by a very long line of text containing "SATA" and "HD" in it, which i assume mean other bootable partitions on the SSD drive (as opposed to the "windows boot manager" or whatever to which the UEFI defaults).

so i selected the USB option and added it to the boot order.

however, b/c i wanted to show a technically challenged friend step by step how to perform the same operation, i wanted to move the USB option out of the UEFI boot order in order to demonstrate the process from scratch.  so i chose the "delete a boot entry" option (or whatever it's called -- the xps 13 is not in front of me right now, sorry) and removed the USB entry from the UEFI boot list, thinking it would return to the list of available options under the "add a boot entry" screen.

well, it doesn't. it just seems to be gone.  which means, if i understand things correctly, that i cannot now boot in UEFI mode from a USB stick (with an EFI partition and bootloader on it).

so i'm stuck.

my question is:

can someone please tell me how i can add the USB ports to the UEFI boot order list given that i accidentally deleted that option? (apparently permanently, which seems like a major design flaw in the UEFI system, as that sort of permanent trashing seems undoable in the legacy BIOS boot order listing)

i believe if i knew the text to type into the appropriate field in the "add boot order entry" screen (by which i mean the original very long string i mention above containing "USB" in it; it also listed "PCI" things in the string -- i think you will know what i'm talking about),  i could just manually type it out, add that to the UEFI boot list, and everything would be kosher.  would that actually suffice?  and if so, can someone else with an xps 13 please type out that string for me here.

i know that i could install ubuntu in legacy mode (as is the default on the developer edition with 12.04), but i'm explicitly trying to experiment with the UEFI installation and booting to see whether there are any hiccups/issues.  i also don't want to wipe the drive b/c i'd like to keep the windows 8 installation (even though i'll rarely use it).  finally, it seems that this UEFI boot order problem would keep me from using a windows 8 USB recovery stick prepared with dell's windows 8 recovery & backup tool to restore my xps 13 to factory settings if i wanted to, since i believe that would require UEFI booting the windows 8 recovery USB stick.

so for a variety of reasons, it is important to me to be able to UEFI boot from a USB stick.

thanks in advance.  i'm really in a bind with this.