How to setup includes for jar plugin using one plain property?

[Andrey Razumovsky]

Hi,

I need to setup includes for jar using just one property, not the
complicated <includes><include>... structure, just the way it can be done
for war plugin. So
1. I've found "maven.jar.includes" property, but I've been unable to set it
for plugin execution. How can I do that?
2. Is it possible to setup a variable with XML tree? Then I would put
something like <includes>${jarIncludes}</includes> to my plugin execution
configuration

Thanks,

-- 
Andrey