Interacting with other programs

I work for a company that does radio analysis and develops maps that predict the behavior of radio waves through algorithms and the use of some terrain data..

The problem is this:

The last batch of data that we ordered (The state of Texas) was contained on 2 CD that contained 6000 tar.rar.gz files AND each zip file contains files with identical names... (Idiot distributors) Anyway I need to go through and extract the data, convert it to another format and then import it into our program..

I have been playing with vc++ for 6 months or so now and I want to write a program that will interface with WinZip and the conversion software to do this for me. How do you interact with other peoples programs? I know that it is possible because of all of the cracking programs that are available, these programs such as the zip password cracker must be able to open a WinZip file try a password and then redo the step thousands of times per second.... I have searched around on this subject and have been unsuccessful in trying to find information in how to do this (program interaction is a vast blanket terms for a lot of things). Can someone help me out?

Thanks in advance,

Jordan Fuerst

Have a look at unzip source. I don't know if it will do tar files but it will definitely do zip files. Anyway, tar format is a generic Unix thing. If you look for a Unix source code repository, you will probably find it there.