question about C arrays

Well, taking that this is true:

char buffer[] = "test";
buffer[1] == 1[buffer]; // ('e' == 'e')
I suppose that when you use [] it's like writting
buffer[1] == *(buffer+1);
so.. why i can't declare an array like

char *(buffer+10);
?

Array access is synonymous with, if not identical to, pointer access. These are interchangeable.

Array declaration and pointer declaration are two different things. The latter gives you a pointer and only a pointer. The former gives you a pointer, a contiguous block of memory to play with (in the stack,) AND points the pointer to the memory block. These are not interchangeable.