> PS: memcpy is safer
No it's not. It will try to copy n characters whether it hits an architecture-dependent read boundary or not. Use strncpy(). It is fully standard and stops in the right place.

To convert a string to an integer #include <cstdlib> and use the atoi() function:
int i = atoi( "42" );

Also, this is the C forum. If you plan to use C++ please post in the C++ forum. While the same people frequent both, the advice you get will vary depending on the language. (C and C++ are significantly different languages.)

Hope this helps.