C++ pomoć - nemam pojma o nićemu

Sa VBom radim jako dugo.  Ovo je iz VB

Private Declare Function OpenDevice Lib "k8061.dll" () As Long

Ne mogu nigdje nać konkretan 'how to' kako to napisati u c++

Da nepomenem da učim na linux-u

uz ovaj dll gore sam dobio demo program koji naravno ne radi, ali sam s njim dobio fajl k8061.h u kojem ova gore linija izgleda ovako:

FUNCTION long __stdcall OpenDevice();

Da li da to shvatim tako da kopiram .dll i .h uz moj projekt i samo includeam .h pa nastavim dalje?

I naravno: ako je to tako - kako kompajliram stvar?

Trenutno kompajliram ovako

gcc -o main $(mysql_config --cflags) main.c $(mysql_config --libs)

(spajam se na mysql  pa zato ovo gore)

http://goffconcepts.com/techarticles/development/cpp/calldll.html

Pitanje 2:

mysql.c započinje ovako:

mySelect(int i, StructDbInfo* dbInfo) {

main.c izgleda ovako:

struct StructDbInfo {
    char *server;
    char *user;
    char *password;
    char *database;
};

main(int argc, char ** argv)
{
    if (argc == 0 || argc == 1) {
       printf("Uporaba: main n\n\n");
       printf("n - redni broj polja\n");
    } else {
       int a;
       a = atoi(argv[1]);
      StructDbInfo dbInfo;
       dbInfo.server = "10.0.96.200";
       dbInfo.user = "root";
       dbInfo.password = "root";
       dbInfo.database = "wikidb";
      
       mySelect(a,dbInfo);

       putLog();
    }
}

Greške se dogode na boldanim linijama:

mysql.c:1: error: expected declaration specifiers or ‘...’ before ‘StructDbInfo’
mysql.c: In function ‘mySelect’:
mysql.c:10: error: ‘dbInfo’ undeclared (first use in this function)
mysql.c:10: error: (Each undeclared identifier is reported only once
mysql.c:10: error: for each function it appears in.)
main.c: In function ‘main’:
main.c:18: error: ‘StructDbInfo’ undeclared (first use in this function)
main.c:18: error: expected ‘;’ before ‘dbInfo’
main.c:19: error: ‘dbInfo’ undeclared (first use in this function)
main.c:25: error: too many arguments to function ‘mySelect’

ideja?