set PATH=C:\wherever\it\is;%PATH%

##</code><code>##

gendef dptcpiphi.dll
dlltool --kill-at --input-def dptcpiphi.def --output-lib libdptcpiphi.a

##</code><code>##

use Inline C => Config => LIBS => '-LC:/my/libs -ldptcpiphi';