I have limited experience with batch files and need some help.

All I'm trying to do is to create a file to open a dos program and EXECUTE commad lines inside the program. I can open the program, but I don't know how to actually execute the code.

Any suggestions?What do you mean "execute command lines inside the program"? What program are you talking about?
When the dos program is opened, it asks you what you want to do. You enter a command and it does it.

By "EXECUTING code" i mean I don't want to have to have to manually type in a set of commands over and over again.

Its an aerodynamics program. I have a lot of CASES to run and I wanted to automate the process.

Maybe you could SHARE the name of the "aerodynamics program" you are being so mysterious about?
AVL

Its a vortex lattice program from MIT.

http://web.mit.edu/drela/Public/web/avl/

Its a free program. I just figured that nobody would care what program it is.
ALWAYS give as much information as possible. Just looking at the website, it looks as if the program was designed to take input from "session files". Don't these do what you want?
Not exactly.

The session files help, however, I have a lot of different scenarios to run. I'd like for it to automatically load the new geometry, run the cases and save the data....and repeat for the next file. Each of these require that the user to type a command line at each of these points. Its just going to be a pain to do this over and over for each case...not to mention time consuming.