  Let $R$ be a principal ideal domain (PID). For a simply connected CW-complex
$X$ of dimension $n$, let $Y$ be a space obtained by attaching cells of
dimension $q$ to $X$, $q>n$, and let $A(Y)$ denote an Adams-Hilton model of
$Y$. If $\mathcal E(A(Y))$ denotes the group of homotopy self-equivalences of
$A(Y)$ and $\mathcal E_{*}(A(Y))$ its subgroup of the elements inducing the
identity on $H_{*}( Y,R)$, then we construct two short exact sequences:
$$\underset{i}{\oplus}\,H_{q}(\Omega X,R)\rightarrowtail
\mathcal{E}(A(Y))\overset{}{
  \twoheadrightarrow}\Gamma^{q}_{n}\,\,\,\,\,\,\,\,\,\,\,\,,\,\,\,\,\,\,\,\,\,\,\,\,\underset{i}{\oplus}\,H_{q}(\Omega
X,R) \rightarrowtail \E_{*}(A(Y))\overset{}{
  \twoheadrightarrow}\Pi^{q}_{n} $$ where $i=\mathrm{rank} \,H_{q}(Y,X;R)$,
$\Gamma^{q}_{n}$ is a subgroup of $\aut(\mathrm{Hom}_{}(H_{q}( Y,X;R))\times
\E(A(X))$ and $\Pi^{q}_{n}$ is a subgroup of $\mathcal E_{*}(A(X))$.
