Access/modify specific row/column of text file - c++

Question

I'm doing some practice in understanding how fstream works, and I've hit a brick wall.
I've initialised a 3x3 text file with each element being 'temp'
I want to be able to access a specific "element", delete it, and then replace it with a string (could be larger or smaller than the current size) but enclosed by the tab characters.
i.e. simulating an edit of a text file
I've been doing some research online, like here: http://www.cplusplus.com/doc/tutorial/files/ but I struggle a lot with implementing it myself.
So the text file, "example.txt" contains:
temp temp temp
temp temp temp
temp temp temp
I'd like to open it for writing, seek the position of say, row 2, column 2 (i.e. corresponding to \n and \t characters), replace it with another string, for example "thisisareplacement"
temp temp temp
temp thisisareplacement temp
temp temp temp
From my understanding, this may not be possible as I'm inputting a much larger size of characters. However I believe somehow defining these \n and \t characters to enclose my strings could give me an opportunity.
Here's my code:
#include <iostream>
#include <fstream>
using namespace std;
int main () {
int numRows = 3;
ofstream myfile ("example.txt");
if (myfile.is_open())
{
for (int i = 0; i < numRows; i++) {
for (int j = 0; j < numRows; j++) {
myfile << "temp\t";
}
myfile << "\n";
}
myfile.close();
}
else { cout << "Unable to open file"; }
// now i want to try and edit a specific row (\n) and column (\t)
return 0;
}