Not to turn this into batchmonks, but you could also get rid of much of the redundancy in that big ol' batch file by using something like this (untested):

:Loop
REM If there are no parameters left, just go run perl
if !%1! == !! goto doit

REM If there's a -L, set the log flag
if !%1! == !-L! set log=1

REM If this isn't a -L, push it on to the params stack
if not !%1! == !-L! set params=%params% %1

REM Shift that %1 off and continue (%2 is now %1, etc)
shift
goto Loop

:doit
if !%log%! == !1! goto Log
c:\devt\perl\bin\perl.exe %params%
goto ciao

:Log
c:\devt\perl\bin\perl.exe %params% > stdout.log

:ciao
set params=
set log=
echo on
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Recursion is your friend!