Concatenates two or more source files into a destination file, 
similar to PIP, but accepts both named directory (DIR) and 
drive/user (DU) specifications, which allows elaborate 
concatenations with input files pulled from various drives and 
user areas.  For ZCPR3 only.  Version 0.6 corrects serious bug in 
version 0.5 (withdrawn), adds Q (quiet) option and error flag 
support, and fixes a couple of bugs.