Is sure looks like the "align=" option wasn't added to DISKPART for creating striped volumes until Windows Vista (it's in there for basic disks back to W2K). Having said that, you might have a shot at doing this by booting a Windows Server 2008 DVD on your machine, breaking out to a command-prompt with Shift-F10 and using DISKPART from there.
I spun up a VMware Server 2.0 VM with two (2) SCSI hard disk drives and the W2K8 Standard x86 install DVD image. I booted, dropped out to a command prompt via repair, and did:
select disk 0
select disk 1
create volume stripe disk=0,1 align=1024
assign volume 0
format c: /q /u /fs:ntfs
After formatting the new volume I shutdown the VM, then attached the two (2) SCSI disks to an existing W2K3-based VM I had sitting around. I booted the W2K3 VM, logged-on and opened "Computer Management" and found that the foreign disks were detected. I imported them and found that my striped volume was accessible. I copied some files to it and found no problems.
Give that a shot. Worst case, if you don't have a W2K8 DVD laying around, download the W2K8 120-day demo DVD and use that.