You can use DSLs in both guided editor rules, and textual rules that use a dsl.

In the guided editor - the DSLs generally have to be simpler - what you are doing is defining little "forms" to capture data from users in text fields (ie as you pick a DSL expression - it will add an item to the GUI which only allows you enter data in the {token} parts of a DSL expression). You can not use sophisticated regular expressions to match text. However, in textual rules (which have a .dslr extension in the IDE) you are free to use the full power as needed.

The DSLs are not automatically included when building a package in the IDE. You need to either use the drools-ant task or use the code shown in the sections above.