rexx: 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 Debian possible default full paths are:

/usr/bin/rexx - from package: regina-rexx

You may install the required package with command apt-get install {package}

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