Consider using what I call a "manager" VI. Its purpose is to manage the file for you.
You call it whever you want to know one of these parameters.
It knows whether it's read the file yet or not. If not, it does so on first call.
After that, it simply keeps all your values in its own memory (shift registers).
When you call it, it simply gives you the value(s) out of its memory, either as a big cluster, or as separated values.
That way, you only read the file once.
Steve Bird
Culverson Software - Elegant software that is a pleasure to use.
Culverson.com
Blog for (mostly LabVIEW) programmers: Tips And Tricks