dont know of a direct one but you could get the 17a from finglas to santry and get the 41, 41b, 41c, 33 to swords. Only posting this option as you've had no feedback, hope it helps.
Thanks for replies, and apologies for worng forum but was in a rush when i posted!!
HAd a fair idea there are no Dublin Bus routes but was checking for private operators. Its a pity because the two places are so close you could cycle - if you were into that sort of thing!! Know a guy who has just move to Finglas and offered a job in Swords, but no car. Even though they are a 15 minute drive apart it could take 90 minutes by bus!! Only in Dublin...
Because HE isn't into that sort of thing (his words)! Though 4 buses - a 3 hour or more round trip - into and from work every day might help to change his mind!