how to import/export dll and use its function

I am developing a project. I want to include a particular function开发者_开发技巧 from 7zip software to decompress data. Its a kinda exporting a particular function from 7zip software to my project. Should I do using DLL import and export or is there any other way?

you should take a look in LZMA SDK, it would give access to 7zip function from C++/C#/C/Java.