Hi. thanks for your reply. Turning it into a actual database would be an option, and perhaps the best route to go here. I'm basically looking for something that will both solve this problem, but that also works as a general method for these kinds of issues, as I run into them quite frequently.

The data is sorted lexicographically on the first number, but this could of course be changed to numerical sorting if that would help. I will look into the tell() and seek() functions, as I'm not familiar with them.