Differential equations in Ward's calculus

In this paper we solve some differential equations in the $D_h$ derivative in Ward’s sense. We use a special metric in the formal power series ring $\text{K}[[x]]$. The solutions of that equations are giving in terms of fixed points for certain contractive maps in our metric framework. Our main tools are Banach’s Fixed Point Theorem, Fundamental Calculus Theorem and Barrow’s rule for Ward’s calculus. Later, we return to the usual differential calculus via Sheffer’s expansion of some kind of operators. Finally, we give some examples related, in some sense, to combinatorics.