FileAppend is to write data to the end of a file.

If your computer name is Alice, then

FileAppend A_ComputerName, "Helloworld.txt"

This changes the text of HelloWorld.Txt to

"Hello World.

Alice"

Where Helloworld.txt will (probably) be in the same folder as your script.

You are asking about the file name, which would be

FileAppend "asdf", A_Computername . " Helloworld.txt"

Filename:

“Alice Helloworld.txt”

Text:

"Hello World

asdf"

FileAppend does create a file, so you can just start calling the file and appending to it with the same command:

MyData := “GIGOasdfasdfasdfasdf” MyPath:= "C:\OutputFolder" . A_Computername

FileAppend MyData, MyPath, `n