Please bear in mind I have no experience in HT-PIC, the following comes from
extensive use of several K&R and ansi C implementations

> vector[counter],

In C an array name (in this case vector) is a pointer to the bottom of the
array, ie

      vector[0]== *vector

Is true

> MyStruct vector[VECTOR_SIZE] at vector_address;
> Vector_adress + 8*counter = value;

(again ansi C) Pointer arithmetic dictates that adding 1 to a pointer
actually increments the pointer to the _next_ element of that data type. A
code example would be...

Char *pc;
Int  *pi;

    pi=pc;

    pi++;
    pc++

    pi!=pc at this point as an int is (usually) 4 bytes and a char is
(usually) 1 byte.

So with that in mind you _could_ do the following

MyStruct vector[VECTOR_SIZE]
MyStruct *vector_address;

*(Vector_adress + counter) = value;

Whether this will help the code size I have no idea, what it does do is
reduce the readability...

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