The quality of creaminess comes into play with a well balanced luxury bar. This is usually associated with a small densely bubbled lather. In your soap calculator the creamy value is the sum of the Palmitic + Stearic + Ricinoleic acids. These are oils like Palm oil, Coffee Bean Oil, Kokuum Butter, Shea Butter, & especially Castor Oil. These are the oils that are the fatty acids that produce lather that is fine textured, and richy and creamy. Ricinoleic, as mentioned before, enhances lather.
But you want to decrease oils/butters that are high in lauric & myristic (which create more bubbles) like Palm Kernel Oil, Coconut Oil, Babassu, etc.
Also, plain olive oil soap is creamy after a very nice long cure.
You can also add milk in place of water for a nice creamy bar.
Superfatting may be affected. Do not forget to figure in the fat percentage of the dairy product. For the most part, general milk products (where the fat percentage is 4-6%), really won’t affect your end bar. However, using a product like heavy whipping cream (which has a fat of 36%) will directly affect your end bar. In this instance, you may what to use the dairy portion of 25% of your water ratio. That is unless you play with your superfatting percentage number.