HANDLE hThread;

DWORD CALLBACK ThreadProc(void *pArg)
{
    while(playnow)
    {
        DWORD delay;
        delay = PtrToUlong(pArg);
        Sleep(delay);
        FunctionB();
    }
    return 0;
}

void FunctionA()
{
	//Code here; read file containing sounds
	

	FunctionB();
}

void FunctionB()
{
	if(runnow)
	{
		//Pick a random song from the file
		//Play the song

		fsystem->update();
		{
			//Set Volume

			//Get song length (in miliseconds)
		}
                DWORD tid;
                hThread = CreateThread(NULL, 0, ThreadProc, ULongToPtr(songlength), 0, &tid);

	}
//More code; should still run and not only after X miliseconds as Sleep(); would do
}

void FunctionC()
{
     //Close file etc
     CloseHandle(hThread);
}