I've done a search in the forum, but I've not seen this post.
Our servers have AIX 5.3 TL04, so I suppose it can be done.
There is also a weird thing. We have put in /etc/security/user that passwords must have at least 3 non-alphabetic characters and a min length of 8. In all our servers except one, if you put a password like qwerty123 it lets you, but AIX will only store as password qwerty12 (less than 3 non-alphabetical), but in one server this will fail, it won't let you put a password if it doesn't have the 3 non-alphabetical in the 8 first characters.