Here is a quick demo that was put together that demonstrates one way to do this.
Effectively, you create tokens in the Richtext of the section (or you could do the same for a straight textbox control I suppose) and do a replace on it.
Demo to replace string tokens in a Rich Text Control
Just save the zip file to you computer, and import the report. It will most likely show up in the "Uncategorized Reports" section. It's called "Rich Text Replace"
-R