you need a pair of loops (it can be done in one, but lets start simple) and a print statement.
to write out a single * you might try
cout << '*';
and to write an end of line try
cout << endl;
and something like
for(j = 0; j < numrows; j++)
for(k = 0; k< numcols; k++)
cout << '*'; //this is in the inner loop.
cout << endl; //this is in the outer loop.
try to avoid using globals. Also the global pointers are not used correctly here.
also, rows and cols in main are not initialized. Keep it simple, try
print(3,4, asg); //what is asg for?? it is not used.