I would suggest you contact customer support to walk you through this, otherwise provide more details here of what part you are trying to create and how many slots/gates. It won't be as quick as talking to customer support but will probably answer your questions. Also take a look at the SampleLib under SDD_HOME/standard/examples there may be a similar component in there that shows you how to do this.
Thanks for the pointer to the example library. when I opened the example library and looked at the TTL Logic partition I looked at the ac245-gate and now I understand in more detail how the slot feature works. That's exactly what I was trying to do with a couple of my symbols.