e.g.
byte[] z = new byte[255];
int a = 10;
int b= 20;

I wanna do sth like

memcpy(&z[10], &a, sizeof(a));

how can I do it in c#?
do I need to do things like

byte[] temp = System.BitConve rter.GetBytes(a );
for (int i=0;i<temp.Leng th;i++
z[10+i] = temp[i];

thx.......