Compare element inside a struct with a void pointer value in C

I need to create a funcion that receive a struct pointer and a void pointer, it return 1 if the element is on the struct.

typedef struct {
    char *sx;
    int val, code, qtty;
    char abc [20];
} ST_DAT;

int compare (ST_DAT *, void *);

This is part of a program that compare nodes in a double linked list, but this funcion is used as:

int (*pfun)(ST_DAT *, void *));

The problem is that I don't know how to compare the void * to the other values until I find or not the value inside.

int compare (ST_DAT *stData, void *key)
{
    if (key == (*stData).val || key == (*stData).code || key == (*stData).qtty || strcmp (key,(*stData).abc) || strcmp (key,(*stData).sx) )
    {
       return 1;
    }else{
       return 0;
    }
 }

Is this correct?