How do i put movies on my ipod without taking existing music off?

i have put two digital copy movies on my lap top and they are in my library. the only problem i have is whn i drag it to my ipod device that it says in order to sync it that it will erase the other 7000 songs on my ipod. is there any way i can put the movies on without having to take my music off? i have already tried to download a program to extract music from my ipod to save it it but it only allows 5 songs at a time so try and do that with 7,000 songs ya know? can anyone please help?