On Win32 Apache is run as a service. The command-line to run is specified in the registry under

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Apache2.2

In my case this is:

"C:\apache2.2\bin\httpd.exe" -k runservice

It isn't as simple as just changing that to something like:

set PERL5LIB=C:\perl\lib;C:\perl\site\lib && "C:\apache2.2\bin\httpd.exe" -k runservice

but possibly some kind of wrapper program could be worked in there which sets PERL5LIB and then runs the service.

I think I'm going to settle for just removing the registry lookup from my perl build, though.