I'm not exactly sure what you're trying to do, but does this answer your question?
Code:
itsme@itsme:~/C$ cat demo.c
#include <stdio.h>
#include <string.h>
int main(void)
{
char buf[100] = "some string";
puts(buf+1);
strcpy(buf+4, "thing else");
puts(buf);
return 0;
}
itsme@itsme:~/C$ ./demo
ome string
something else