Need help for c++ address parameter

my progam in cpp
```cpp
// in h
typedef struct
{ BYTE attr
 /* some other attrs */
} STRUCT, *PtrSTRUCT;
LONG __stdcall foo(PtrSTRUCT ptr);
// in cpp 
STRUCT myStruct;
bar = foo(&myStruct);
```
how to do this in fastcall way?