Since both the 3DS and ASE formats originate from 3D Studio Max 3D animation software it would be your best, and probably also only choice how to convert 3ds to ase, ie. to export 3D Studio Max graphics (.3ds) to ASCII scene export files (.ase). Such 3ds to ase conversion or export might also be possible with some 3rd party conversion utilities like the 3D Object Converter.
Open 3DS file Open ASE file3D viewer and converter with huge file type support
A command line converter for 3D format