[R] building and installing a package in Windows

[Yev Kirpichevsky]

I'm trying to install a package in windows.  I have a package directory, 
which contains all the essentials: .Rd in the Man directory, DESCRIPTION 
file, etc.  I copied it to my R\bin directory, where the Rcmd file is located.
Then, when I try to run "Rcmd build mypackage" from that directory in DOS, 
I get the following error: "'perl' is not recognized as a command..."
I would appreciate any help on this matter.  Thank you very much!
-Yevgeniy