Hi @hsendel
please check the workflow
In this workflow, u can see sample text file in which there are many lines
i am searching misquote word i had assigned the word to input variable
and at last it is writing back to same text file
word_file.zip (31.8 KB)
for ur clarification u can see that which word u want to search u want assign in input variable, in my case i had assigned with “misquote” u can see in image
Hope it helps
Mark it as solution if got it
Nived N 
Happy automation