File Write li Help

I want to make a text file just like this:

-----------------------------------------------------------------------------------------------------------------------

[computers]

30

[IpBanned]

82.77.88.163

[Mail]

dasdsa@dadsa.com

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my question is how can i edit with writeline() lets saythe 4 row(82.77.78.163) when i am trying to write something with writeline() or write() it`s always starting from the beginning, is there a function like this

write(string, row)

 

Can anyone tell me