helcor: 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/helcor - from package: munipack

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

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