cdo: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/cdo - from package: cdo

You may install the required package with command apt-get install {package}
Error in other languages:
cdo: bevel nie gevind nie
cdo: comandă negăsită
cdo: comando não encontrado
cdo: commande introuvable
cdo: command not found
cdo: käsku ei ole
cdo: không tìm thấy lệnh
cdo: komanda nerasta
cdo: Kommando nicht gefunden.
cdo: kommandot finns inte
cdo: komut yok
cdo: nie znaleziono polecenia
cdo: níor aimsíodh an t-ordú
cdo: no se encontró la orden
cdo: no s'ha trobat l'ordre
cdo: opdracht niet gevonden
cdo: parancs nem található
cdo: perintah tidak ditemukan
cdo: príkaz nenájdený
cdo: příkaz nenalezen
cdo: команда не найдена
cdo: командата не е открита
cdo: 命令找不到
cdo: コマンドが見つかりません