Key Press Trigger for word or phrase?

I’m building a system in which a barcode scanner inputs the location of various files. For the sake of this question, let’s say the scan inputs either of the following text into the textbox of a program:

x:\big\file.jpg
x:\small\file.jpg

I would like to do something different if the words x:\big\ or x:\small\ are sent to the textbox in a program. It seems that “Key Press Trigger” only works with specific keys and not words. Is there a combination of other features that would allow for this? I assume anything could be made with a VB script, but I’m not much of a coder.

@richarddenton was working in similar concept.He might help you.