  We investigate the A$(\pi^+,K^+){_\Lambda}$A reaction within a covariant
model. We consider those amplitudes which are described by creation,
propagation and decay into relevant channel of $N^*$(1650), $N^*$(1710), and
$N^*$(1720) intermediate baryonic resonance states in the initial collision of
the incoming pion with one of the target nucleons. The bound state nucleon and
hyperon wave functions are obtained by solving the Dirac equation with
appropriate scalar and vector potentials. Expressions for the reaction
amplitudes are derived taking continuum particle wave function in the plane
wave approximation. Numerical calculations are presented for reactions on
$^{12}$C, $^{40}$Ca, $^{51}$V and $^{89}$Y target nuclei. The predictions of
our model are in reasonable agreement with the available experimental data.
