umm well im just gonna wing this cause ive never done it before,
set your srand((unsigned)time(0));
rand_NUM[5];
for loop
rand_NUM[i] = (rand()%+(amount of lines from text file))+1 use a counter with a while loop
fstream file("file.txt");
while loop (getline(File,line,'#'))
establish your counter
if(line == rand_NUM[i])
cout<<line<<endl;
i dont really know but probably something along those lines, jus play around with it