Maybe this is it? From the readme file:
WAV-PRG 2.3 By Fabrizio Gennari, 1998, 2001
This programs runs on Windows 95/98/NT. It does two things:
- converts Commodore 64 tape files to PC in emulator-readable format (.PRG,
or .T64), so they can be played with PC emulators. Tapes can be converted
WAV or TAP samples, or directly from the sound card. In order to recognize
different file formats, WAV-PRG uses a plug-in architecture: each plug-in
recognizes a different file format.Plug-ins for Turbo Tape 64, kernel loader
(the "slow" loader built-in in C64 ROM) and Zzap! Megatapes are included,
plug-ins for many other formats can be written. In order to be used by
the plug-ins must be copied in the plugins sub-directory.
- converts programs from .PRG, .P00 and .T64 files to WAV files, which can
recorded on a tape and loaded on a Commodore 64 as Turbo Tape 64 files.