Hi Larry,
A while back, there was a user who had a machine shop make up a number of expanders for .223. If you do a search, you should be able to find that thread. I have one from another source. I'm not planning to sell it, but if Dave Wilson wants to copy it, I would be happy to lend it to him. (not that he would need it.)
For the tool head that you have which is uses 7/8" dies, you really don't need an expander. 7/8" sizing dies include an expander ball that expands the neck while sizing and depriming.
Dillon included some special links with his SuperStar kit. They did not increase the leverage. They only made it so you could raise the tool head about 1/8" to 1/4" higher.....until the tool head contacts the crank shaft assembly. You really don't need those links to load .223.
There are a number of members on this forum who are loading .223 on Stars. Maybe they will pipe in with some recommendations.
I'm pretty new to rifle loading myself, but I thought the bullet was held in place by neck tension on a .223. At least that is what I have been doing, and they shoot pretty darn good.
Bruce