Why do I need to qualify commands with full path name?

I am puzzled as to why I have to qualify CODE's external commands with the full 
path when writing REXX scripts but not from the editor's command line.   The 
program command files are in D:\WDT400 (which is also in the DOS path).  I can 
run these commands interactively without fully qualifying them but if I use 
them in a REXX script I do.

Even when I use the directory() function to change the current directory to 
D:\WDT400 the path name still has to be qualified.

This is problematic when using CODESRV to communicate with Turnover's interface 
as I need to pass a large string and compress the command parameter entries as 
much as possible due to the 128 character size limitation of the command 
parser.  So far I've been able to modify TURNMAKE.LX to eliminate the parameter 
labels by rearranging the positioning of the parameters (and removing some 
where the defaults are acceptable) but I need to squeeze out a few more 
character positions and not having to enter the path of the REXX command just 
might do it.

Don Freeman
Norcal Waste Systems, Inc.
http://www.norcalwaste.com