typedef unsigned long DWORD;
unsigned char as[] = {"1234"};
#define LN2DWORD(a) ((((DWORD)(a[0]))<<24UL)|((DWORD)(a[1])<<16UL)|((DWORD)(a[2])<<8UL)|((DWORD)(a[3])))
int main()
{
printf("0x%08lx\n", LN2DWORD(as)); // 0x31323334
printf("0x%08lx\n", LN2DWORD("1234")); // 0x31323334
return 0;
}