You can do this. Keep in mind that the DSL engine will try to match each dsl mapping
entry into the LHS of the rule, one by one, in the order they are declared in the mapping
file. This means you can have one mapping that substitutes the word "and" for a
comma, and so on. It may take some clever mapping, and multiple entries to get the
flexible effect you're looking for, but it's doable (I've done it).
You might find the typed variable support in Drools 5 helpful. There's a blog post
about it, and a few weeks ago I posted a more detailed answer to essentially the same
question to the list, if you want to go through the archives to find it.
This may help...
http://article.gmane.org/gmane.comp.java.drools.user/11020/match=geis
Matt Geis