A Special Program

I've created the design of it, I just have no clue how to load.

Basically, there is a Dropdown box that connects to a folder. In the folder, are txt files. I need w/e text files are there on startup to be shown, in the dropdown box. Then, I need it so when somemone selects one of the files in the dropdown box, it read's the text file and performs some tasks. (I am getting really confused on how I could do this)

So basically, the dropdown is just for selecting the Text File.

In the textfile would be things like this:

open {test.java} (This would internally open the named java/ or whatever file)
find {test} (This would find the word test in the file)
add {testadd}, {under} (Would add "testadd" underneath The searched "test"}
remove {testadd} (Would remove "testadd")
save {test.java} (would save)
stop {c:/location/compile.bat} (Would Basically load the bat file.)


As if this wasn't complicated enough, then how would I get the compile.bat stuff (Like the log that comes from it, etc) to show up in a rich text field?
I cannot figure this out O_O