in reply to
MakeMaker tailoring

Do you have to make and install the `EnvProcessDll` dll separately? If not, you might take the approach of
Math::FFT; in this, there's an XS file (`FFT.xs`), plus a couple of pure C files (`arrays.c` and `fft4g.c`) to supply some needed functions. The
associated Makefile.PL:

`my %opts = (
'NAME' => 'Math::FFT',
'VERSION_FROM' => 'FFT.pm',
'OBJECT' => 'FFT.o fft4g.o arrays.o',
);
WriteMakefile(%opts);
`

writes a Makefile to compile and link all the files needed to build the extension.