That format is for Ultracompressor II, an ancient proprietary archive format from the early 1990s. It was designed for MS-DOS so It's very unlikely that you'll be able to find a Win32 compatible application. If you can get your hands on the DOS application you may be able to run it in DOSBox
EDIT: found them
http/www.bttr-software.de/freesoft/arc1.htm
If you need an activation code for the product the author has provided this one for the community to use. The source code is also available from his website here http
/www.nicodevries.com/professional/
Ultra compressor II revision 2-3 PRO #/2650815932 security code: 7037