Logfile for InstallShield Compiler..

I running perl scripts on windows to compile and build my Installshield
Setups. I am logging the perl output to STDOUT into a logfile using the
select command. Unfortuneatly, the ICompile.exe and IBuild.exe I call with
system, have their own STDOUT and so that information doen't appear in my
logfile. Same for WindowsScriptingHost..
Is ist possible to capture the output of other Executeables I call with
system, or is there another way to call these applications?

Thanks, Jens