gddccontrol: 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

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/gddccontrol - from package: gddccontrol

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