Other monks have already mentioned the appropriate modules. Here is the logic for the pseudo-code

1. Grab the entire page, usually in a scalar
2. Extract from the above scalar the "particular" line based on the expected pattern

A module such as LWP does precisely what is suggested in (1) above. See the cookbook for a trivial example. If your "particular" line pattern is not too tricky, (2) above should also be a trivial regexp exercise.

Good luck.