May I suggest for next time that you don't copy the headers you add the 'C:\perl\lib\core' to the commandline. There should be a commandline switch for bcc32 to add directories for the compiler to find .h files not in the standard include directory 'c:\Borland\Bcc55\include\'.

From here

To add include directories,
you need to specify   -I"<directory>;<directory>."