In order to create a QAC in a location other than the default, according to the vastool documentation you should be able to just pass in the location of another container to the "vastool configure ad" command, however that command ignores that option and tries to create the object in the default location anyway. This can be demonstrated on a DC where the default location does not exist:
root@pmadmin ~ # vastool -u pmadmin configure ad "CN=QAC,DC=pfm,DC=hal,DC=lab"
No domain specified, configuring joined domain pfm.hal.lab (to configure a different domain run "configure ad -d <domain> ")
Password for pmadmin@PFM.HAL.LAB:
ERROR:
Error creating QAS application configuration (error 4).
ERROR: VAS_ERR_LDAP: LDAP error
Error encountered processing ldap result for dn [CN={786E0064-A470-46B9-83FB-C7539C9FA27C},CN=Authentication Services,CN=Quest Software,CN=Program Data,DC=pfm,DC=hal,DC=lab], err=0000208D: NameErr: DSID-03100238, problem 2001 (NO_OBJECT), data 0, best match of:
'DC=pfm,DC=hal,DC=lab'
.
Caused by:
LDAP_NO_SUCH_OBJECT: No entry found on server