if anybody could give me a hint as to how to get started on this, I'd be very much in your debt

Read your course notes! Ok, these are the steps:
open the file
Use a while loop to read a line from the file handle
Within the loop, split the line around the field delimiter, extracting the relevant columns.
Test the data found against that required. If found, leave the loop.
Outside the loop, close the file handle
print the result.