BEGIN {FIELDWIDTHS = "12 14 8 2 3 3 8 1 3 14 14 3 8 14" }
it seems that this FIELDWIDTHS is restricted to gawk, but not to all implementations of awk, in particular not to the one in MobaXterm. However MobaXterm has the possibility of installing programs and plugins. Thus I try
[andres.ANDRESLEGAR2422] → apt-get
apt-cyg: Installs and removes Cygwin packages.
"apt-cyg install <package names>" to install packages
So, I install it
[andres.ANDRESLEGAR2422] → apt-get install gawk
Trying to download file setup.bz2
Updated setup.ini
Found package gawk
Downloading gawk-4.1.3-1.tar.xz...
Unpacking gawk-4.1.3-1.tar.xz...
Extracting dependencies for usr/bin/gawk.exe...
Extracting dependencies for usr/bin/gawk-4.1.3.exe...
Extracting dependencies for usr/libexec/awk/pwcat.exe...
Extracting dependencies for usr/libexec/awk/grcat.exe...
Extracting dependencies for usr/lib/gawk/filefuncs.dll...
Extracting dependencies for usr/lib/gawk/fnmatch.dll...
Extracting dependencies for usr/lib/gawk/fork.dll...
Extracting dependencies for usr/lib/gawk/inplace.dll...
Extracting dependencies for usr/lib/gawk/ordchr.dll...
Extracting dependencies for usr/lib/gawk/readdir.dll...
Extracting dependencies for usr/lib/gawk/readfile.dll...
Extracting dependencies for usr/lib/gawk/revoutput.dll...
Extracting dependencies for usr/lib/gawk/revtwoway.dll...
Extracting dependencies for usr/lib/gawk/rwarray.dll...
Extracting dependencies for usr/lib/gawk/testext.dll...
Extracting dependencies for usr/lib/gawk/time.dll...
Package gawk requires the following packages, installing bash cygwin libgcc1 libgmp10 libintl8 libmpfr4 libreadline7
Package bash is already installed, skipping
Package cygwin is already installed, skipping
Found package libgcc1
Package libgcc1 is already included, skipping
Found package libgmp10
Installing libgmp10
Downloading libgmp10-6.1.0-3p1.tar.xz...
Unpacking libgmp10-6.1.0-3p1.tar.xz...
Extracting dependencies for usr/bin/cyggmp-10.dll...
Package libgmp10 requires the following packages, installing cygwin
Package cygwin is already installed, skipping
Package libgmp10 installed.
Found package libintl8
Package libintl8 is already included, skipping
Found package libmpfr4
Installing libmpfr4
Downloading libmpfr4-3.1.4-1.tar.xz...
Unpacking libmpfr4-3.1.4-1.tar.xz...
Extracting dependencies for usr/bin/cygmpfr-4.dll...
Package libmpfr4 requires the following packages, installing cygwin libgcc1 libgmp10
Package cygwin is already installed, skipping
Found package libgcc1
Package libgcc1 is already included, skipping
Package libgmp10 is already installed, skipping
Package libmpfr4 installed.
Found package libreadline7
Package libreadline7 is already included, skipping
Package gawk installed.
Rebasing new libraries
Found package rebase
Installing rebase
Downloading rebase-4.4.2-1.tar.xz...
Unpacking rebase-4.4.2-1.tar.xz...
Extracting dependencies for usr/bin/rebase.exe...
Extracting dependencies for usr/bin/peflags.exe...
Package rebase requires the following packages, installing coreutils cygwin grep gzip sed
Found package coreutils
Package coreutils is already included, skipping
Package cygwin is already installed, skipping
Package grep is already installed, skipping
Found package gzip
Package gzip is already included, skipping
Found package sed
Package sed is already included, skipping
Package rebase installed.
Then I change in the scripts to use /bin/gawk.exe
Now everything seems to work fine.