#! perl -slw
use strict;
use Win32::API::Prototype;

ApiLink( 'kernel32', q[ 
    HMODULE GetModuleHandle( char *lpModuleName ) 
] );
ApiLink( 'kernel32', q[ 
    DWORD GetModuleFileName( HMODULE hModule, LPTSTR lpFilename, DWORD nSize )
] );

my $name = chr(0) x 256;;
GetModuleFileName( GetModuleHandle( 'perl58.dll' ), $name, 256 );
print $name;

__END__
c:\test>570085
c:\perl\bin\perl58.dll