Use a seperator that wont be used in any lines of text, like ; .
You make your ini like this:
[Langs]
Line1="Esto es un test;This is a test"
To get the correct language lines, use this:
local Lang1 = ReadIniString( "Langs.ini", "Langs", "Line1" );
local esp = GetTok( Lang1, ";", 0 ); //This will get the first part of the whole line, untill the first ; is found
local eng = GetTok( Lang1, ";", 1 ); //You can probably fill in what this thing does here..
Hope that helps you out.