There is a program called ADFrom which reads a ADF tape21 file and writes out Molden Format. The ADFrom program was developed by Fabio Mariotti and Prof. Alessandro Bencini from the University of Florence, Department of Chemistry. The latest update you can get from Fabio's own ADFrom site (including support). In fact the early command structure used by ADFrom was the first model for the Molden Format.
ADFrom also supports normal modes.
As of yet NO support for the electrostatic potential.