 He was capped 10 times by the Scotland national under-21 team.Lappin was born in Glasgow and began his career in St Mirren's youth system, signing a professional contract in July 1999.He had ambitions to stay-on at school, take his Highers and become an airline pilot, but St Mirren's Head of Youth Development at the time, Joe Hughes, who lived near to the Lappin family, persuaded his parents that he had the talent to make it in football and he left school to sign for the club.