NSIS FileRead conditional override

Question

I should please need your help as I am not a programmer (please have mercy with me). I should need to add in an existing NSIS script a function that does the following:

Checks the presence of a value called 169.254.1.1 into a INI file named myfile.ini and placed in

c:\mydirectory

Should it find this value into myfile.ini it should not do anything else (i.e. let the script do the next steps).

Should it NOT find this value into myfile.ini it should override the file

with another one by silently copying it from c:\dummyfile\myfile.ini

and then let the script do the next steps.

I do not know how to tell NSIS to do this, may I please ask for your help?

Thanks in advance for your expertise.

Meleena.