Sandra, I think you should take a different tack with your enquiry (you might have tried this already; I haven't checked): as the latest event for your Egans was their immigration to Australia, try a post on the Australia board, with all the information you have about when they arrived, all the names of everyone who came out, where they went to, the ship etc etc. - anything you have.
If we can find some arrival information for the family, we might be very lucky and find out something about where they embarked from, and possibly even where they originated. You never know - some of the assisted immigrant records are really good about recording information.
As aghadowey says, it's really hard to find anything in Ireland unless you have quite specific information about where a person came from. Even when you know that, you may not find out anything else, as is the case with my own Irish families!
Cheers
Prue