"Two days ago I had two Irish girls at my hostal..." How lucky for you, Antonio!

The timing of the flights isn't very good but you can get to Shannon on Virgin Express (via BRU & LGW). I think it would require an overnight stay at either Brussels or London. ( http://www.virginexpress.com )
Of the two, I would choose Brussels because the airport is closer to town. I don't know about Dublin - there may be a better connection. But I always fly into and out of Shannon.