het_export: 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/het_export - from package: csound-utils

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