To configure IIS to run perl script:
http://support.microsoft.com/default.aspx?scid=KB;EN-US;Q150629&

To configure PERL script mapping
WARNING: Using Registry Editor incorrectly can cause serious, system-wide problems that may require you to reinstall Windows NT to correct them. Microsoft cannot guarantee that any problems resulting from the use of Registry Editor can be solved. Use this tool at your own risk.

Start Regedt32.exe and open the following registry key:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W3SVC \Parameters\ScriptMap
Click Add Value from the Edit menu.
The Value Name is .pl
The Data type is REG_SZ.
The String value is \perl.exe %s %s

NOTE: The "%s %s" is case sensitive. (e.g. "%S %S" will not work).
Restart the WWW service.
Now that the registry has been configured, you can test the PERL script with your browser. Using the defaults directory structure with IIS, the URL would be the following:

http:///scripts/helloworld.pl?