mcopidl: command not found

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 CentOS possible default full paths are:

/usr/bin/mcopidl - from package: arts-devel

You may install the required package with command yum install {package}

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