Automator - Loop through a text file and process data through a 3rd party software

Question

Just stumbled on Automator the other day (I am a mac n00b) and would like to automate the processing of a text file, line-by-line, using a third party tool.  I would like Automator to loop through the text file one line at a time, copy the string and keep as a variable.  Next, place the variable data (copied string) into the text field of the 3rd party software for processing.  Once the processing is complete, I would like Automator to fetch the next line/string for processing.  I see items like "copy from clipboard" and  "variables" within the menu but I am not finding much documentation on how to utilizle this tool.  Just hear how potentially powerful it is. 
The 3rd party software is not a brand name, just something made for me to process text.  I may have to use mouse clicks or tabs + [return] to navigate with Automator.  A term I heard on Bn Walldie's itunes video series was "scriptable software" for which I don't think this 3rd party app would be. 
Kind regards,
jw

Answer 1

Good news and bad news...
The good news is that it should be entirely possible to automate your workflow.
The bad news is that it will be a nightmare to implement via Automator, if it's even possible.
Automator is, essentially a pretty interface on top of AppleScript/Apple Events, and with the pretty interface comes a certain stranglehold on features. Knowing how to boil rice might make you a cook, but understanding flavor profiles and ingredient combinations can make you a chef, and it's the same with AppleScript and Automator. Automator's good at getting you from points A to B but if there are any bumps in the road (e.g. the application you're using isn't scriptable) then it falls apart.
What I'm getting at is that your requirements are pretty simple to implement in AppleScript because you can get 'under the hood' and do exactly what you want, as opposed to Automator's restricted interface.
The tricky part is that if no one else can see this app it's going to be hard to tell you what to do.
I can give you the basics on reading a file and iterating through the lines of text in it, and I can show you how to 'type' text in any given application, but it may be up to you to put the pieces together.
Here's one way of reading a file and working through each line of text:
-- ask the user for a file:
set theFile to (choose file)
-- read the file contents:
set theFileContents to (read file theFile)
-- break out the lines/paragraphs of text:
set theLines to paragraphs of theFileContents
-- now iterate through those lines, one by one:
repeat with eachLine in theLines
  -- code to perform for eachLine goes here
end repeat
Once you have a line of text (eachLine in the above example) you can 'type' that into another application via something like:
tell application "AppName" to activate
tell application "System Events"
          tell process "AppName"
  keystroke eachLine
          end tell
end tell
Here the AppleScript is activating the application and using System Events to emulate typing the contents of the eachLine variable into the process. Put this inside your repeat loop and you're almost there.