When is a man prohibited from touching a ten-year-old girl, and is it permissible for him to shake her hand and kiss her out of compassion, not lust?

It is forbidden for a man to touch a woman who is unlawful to him, whether by shaking hands or otherwise, with or without lust, for the Prophet, peace and blessings be upon him, said: "For one of you to be stabbed in the head with an iron needle is better for him than to touch a woman who is unlawful to him." Touching is more forbidden than looking, and it is a means to adultery. A ten-year-old girl is usually desirable, so she takes the ruling of all other women.