How to compare a string

[asees]

Hello all,

I am new to NSIS forum. I am impressed with NSIS so i am trying to develop some application for my work through NSIS.I need some clarification.
I am using NSIS 2.0

Scenario:
While performing installation, i need to read a version value from a address.txt file which is already availabe in my system (ex: 8.0.50727.6195).
This version value exists inbetween in the sixth line of address.txt file.
For example the 6 line looks like (<assemblyIdentity type="win32" name="Microsoft.VC80.DebugCRT" version="8.0.50727.6195" processorArchitecture="x86" ).
After reading i need to compare the same value which is availabe as a part of my installation. If both are same then i need to proceed with the installation or else i need to quit the installation.

Questions:
1. How can i compare the version value from the address.txt file and the txt file available as a part of installation
2. How to read a version value from middle of the sixth line

[MSG]

1: VersionCompare http://nsis.sourceforge.net/Docs/AppendixE.html#E.3.16
2: WordFind probably. http://nsis.sourceforge.net/Docs/AppendixE.html#E.3.16