  Feynman integrands are constructed as Hida distributions. For our approach we
first have to construct solutions to a corresponding Schroedinger equation with
time-dependent potential. This is done by a generalization of the Doss approach
to time-dependent potentials. This involves an expectation w.r.t. a complex
scaled Brownian motion. As examples polynomial potentials of degree $4n+2,
n\in\mathbb N,$ and singular potentials of the form $\frac{1}{|x|^n},
n\in\mathbb N$ and $\frac{1}{x^n}, n\in\mathbb N,$ are worked out.
