TrueImageCMD: no vm_type XenServer?

Hi everybody

I would like to convert a True Image file into a .vhd file and import it into XenServer. This is the command I would like to use:
trueimagecmd /convert /filename:C:\image.tib /target_filename:C:\convimage.vhd /vm_type:????? /harddisk:1

How can I specify the vm_type XenServer? The CLI only offers the parameters /vm_type:[vmware|esx|microsoft|parallels] whereas the GUI offers XenServer as well?

Thanks for your help
Stefan