//Pre conditions: MAX_LINES is an interger that "knows" the number of lines the file has
//heres a little something, its more like psedo code
...Somewhere in the method...
int randomLine = nextInt(MAX_LINES); // Gets a random interger from 0 to end of file
while (int i = 0; i < randomLine; i++)
input.readLine(); // goes to the the random line - 1
String line = input.readLine()); // now that we're at random line -1 read it again and it will be the random line, now actually store the line.
...Do something with the line read in...
hope thats helpful, not sure on the columns