[Rd] for help on building a R package with several R function and a bunch of c, c++

[alex46015 at yahoo.com]

Hope I can get quick help from here, I have a bunch of c, c++ included main function and makefile. It works well on both UNIX and windows. I tried to build R package which include this C++ program and several other R functions.  These R function here are independent  of c++ code. I prefer to define one R function to call this c++ program (main function). 

I know how to build R package with just R function, but I don't know how to handle those c++ c code after I copied those  code  in ./src, I am reading manual "Writing R Extensions" , but I did n't catch the key point . Do you know any easy way to do it? ,

Thank you in advance! 

Alex