What do do about missing export DLL

I have an application called CYGWIN which is basically a unix-like environment that runs under W98. Apparently, I was missing a CYGWIN file on one of my PCs called "cal.exe ". So, I copied it off of another PC to the one that was missing it. When I tried to run it, I got a message that said it couldn't find a particular .DLL file. I copied the missing .DLL file, tried to run it again, and got a message regarding another missing .DLL file. I copied that one, and now when I run "cal" I get: "CYGICONV-2.DLL file is linked to missing export C:CYGWIN1.DLL:_fopen64 ". I tried to copy the file CYGWIN1.DLL, but got a message that there was already one there. I stopped at the point, and did not copy the file. What can/should I do now?

Thanks.