Don't be dismayed by the size of the article. It contains what you are looking for. There are a number of ways of replicating data in a document and which is best takes some thought. If anyone suggests which you should use without knowing a lot more about what you are trying to do it is not all that helpful.

I suspect the most elegant are content controls mapped to custom properties. That lets you change a value anywhere in a document and have the result show up in all the other locations. However, that is not as simple to set up as some other methods.