When an ESL application attempts to read or write a file to disk with no path specified, ESL will use which ever directory the application is running from. For example, if an ESL program is run from the C:\Program Files\EslSyndetic directory, and the program writes out a file, it will be written out to the C:\Program Files\EslSyndetic directory.
When an ESL application attempts to read a file from disk, with no path specified, only the directory the application is being run from is searched. However there is a setting available in the EslConfig.ini file (or Environment Variable) called "TEXTPATH". This setting allows you to control the directories to search when reading files into textual regions and list boxes (including combination boxes), but not FILEIO files. TEXTPATH specifies additional directories (other than the current) for ESL to search.