How to automate adding guest to host inventory when host managed by vCenter

I want to be able to programmattically add virtual machines to the  inventory of  vCenter.  I.e. I don't want to have to add them  interactively via the vSphere gui.  The following KB article says that  you can do so from the command-line of an esx host, but that you  shouldn't if you manage the host via vCenter, because if you do, then  you "may cause a mismatch between the host and the vCenter Server  inventory and may cause unexpected results"

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1006160

I do use vCenter, so I assume then that I shouldn't use the command-line method shown in that KB.

Is  there some other command-line or API way to add guests to the inventory  that wouldn't cause a problem with vCenter?  Can I do this via the  vSphere VCLI, for example?

Thanks,

Jon