Blessings for sale

Walking around Aachen today, we met 4 sweet children all dressed up in honour of St Foillan. From what we could gather, they were selling blessings in his name. A 1 Euro coin in their collection tin bought us a sticker sporting the cryptic code 20*C+M+B+12. They told us to put the sticker up over the entrance to our house in order to be 'blessed.' Hmm, maybe I ought to buy a lottery ticket next.

Being the worst kind of lapsed Catholic, I haven't got a clue who this saint was or what he did except that he was Irish, and there's a very good Belgian beer, St. Feuillien, named after him.

Can anyone tell me more?