how to pass array of structs from Matlab to external C library?

I am able to successfully call functions in my external C library from Matlab. However, I do not know how to pass an array of structures from Matlab to my C library. The following illustrates what I want to do.

1) assume my C library has a structure defined as follows:

struct MyStruct { int X; int Y; }

2) an array of these structures is passed to a function on my C library. For example:

void MyFunction( struct MyStruct* ptr, int count ) 
{
   for( int x = 0;  x < count;  ++x )
      printf( "index %: x = %i, y = %i", x, ptr[x].X, ptr[x].Y );
}

3) In Matlab, I create an array of structures:

arrayOfStructures(1).X = 1;
arrayOfStructures(1).Y = 2;
arrayOfStructures(2).X = 3;
arrayOfStructures(2).Y = 4;
arrayOfStructures(3).X = 5;
arrayOfStructures(4).Y = 6;

4) My question is, how do I pass 'arrayOfStructures' to 'MyFunction' in my C library? I can successfully pass a single structure but not an array.

Thanks,

Ian