It very much depends on what type of company it is and what skilled you lack within your existing management structure. For example do you need financial, sales, technical, legal, HR or market development skills (a German director if you are exporting to Germany, someone who can develop a channel to market etc)?
No matter what the skill it that you require it will take time, effort and luck to find the right person. They need to know your product/ service sector and you need to be able to work with them on a personal and professional level.
The Enterprise Ireland/ county enterprise board sponsored business angel programme would probably be a good place to start if it’s general business experience that you need but from a few people I have talked to the business angel may well be looking at you from more of a VC perspective.