Can a girl get pregnant if shes a virgin but has dry cum on her hands?

The only thing that matters is if the girl has reached puberty, and a live sperm cell enters her vagina at the right time, and makes it to an egg to fertilize it. Sperm - dried or not- on your HANDS- no. On/in your vagina, not likely, but possible. It is not necessary that sperm reach the vagina during intercourse (sex), only that sperm DOES reach the vagina. Wash your hands thoroughly, and use Birth Control if you do not intend to become pregnant- or do not have sex.