Planner-list Error in build script for Windows

Hello everybody out there using Planner,
When trying to build Planner on Windows with the script build-0.14.4.sh, 
the compilation process fails with the message
"../include/libxml/encoding.h:28:19: error: iconv.h: No such file or 
directory"
There were already a couple of errors due to outdated dependencies of 
libpng before, but I was able to fix them down successfully by migrating 
to newer ones.
Could anyone help me to find a way to get more information on the reason 
for the error concerning iconv.h to build Planner on Windows successfully?
Thanks in advance,
Julia