  For $\nu\in[0,1]$ and a complex parameter $\sigma,$ $Re\, \sigma>0,$ we
discuss a linear inhomogeneous functional difference equation with variable
coefficients on a complex plane $z\in\mathbb{C}$: \[
(a_{1}\sigma+a_{2}\sigma^{\nu})\mathcal{Y}(z+\beta,\sigma)-\Omega(z)\mathcal{Y}(z,\sigma)=\mathbb
F(z,\sigma), \quad\beta\in\mathbb{R},\, \beta\neq 0, \] where $\Omega(z)$ and
$\mathbb{F}(z)$ are given complex functions, while $a_{1}$ and $a_{2}$ are
given real non-negative numbers. Under suitable conditions on the given
functions and parameters, we construct explicit solutions of the equation and
describe their asymptotic behavior as $|z|\to +\infty$. Some applications to
the theory of functional difference equations and to the theory of boundary
value problems governed by subdiffusion in nonsmooth domains are then
discussed.
