\documentclass{article}
\usepackage[plain]{automultiplechoice}
\begin{document}

\makeatletter
\newcommand{\sequence}{%
  \message{^^JSEQUENCE(\amc@seq)^^J}%
  \global\edef\amc@seq{}%
}
\def\amc@seq{}
\newcommand\type[1]{%
  \setgroupmode{gr}{#1}%
  \message{^^JTYPE(#1)^^J}%
}
\newcommand\un[1]{{\let\protect\@unexpandable@protect%
      \global\edef\amc@seq{\amc@seq #1}}}
\makeatother

\element{gr}{\un{A}}
\element{gr}{\un{B}}
\element{gr}{\un{C}}
\element{gr}{\un{D}}
\element{gr}{\un{E}}
\element{gr}{\un{F}}
\element{gr}{\un{G}}
\element{gr}{\un{H}}
\element{gr}{\un{I}}
\element{gr}{\un{J}}
\element{gr}{\un{K}}
\element{gr}{\un{L}}
\element{gr}{\un{M}}
\element{gr}{\un{N}}
\element{gr}{\un{O}}
\element{gr}{\un{P}}


\def\essai{
\insertgroup{gr}\sequence
\insertgroup{gr}\sequence
\insertgroup[5]{gr}\sequence
\insertgroup[4]{gr}\sequence
\insertgroup[3]{gr}\sequence
\insertgroup[3]{gr}\sequence
\insertgroup[4]{gr}\sequence
\insertgroup[5]{gr}\sequence
\insertgroup[5]{gr}\sequence
\insertgroup[4]{gr}\sequence
\insertgroup[3]{gr}\sequence
\insertgroup[3]{gr}\sequence
\insertgroup[4]{gr}\sequence
\insertgroup[5]{gr}\sequence
}

\type{fixed}
\essai
\type{withoutreplacement}
\essai
\type{cyclic}
\essai
\type{withreplacement}
\essai

\type{cyclic}
\copygroup[11]{gr}{dest}

\message{^^JCOPY^^J}

\insertgroup{dest}
\sequence

%\setgroupmode{dest}{zozo}
%\insertgroup{dest}
%\sequence

\end{document}
