DosBox v 0.65, PC w/winxp, pentium 1+GB/s, 1GB ram

When I launch a DOS program (this is not a game program) the DOS window says:
mount C "C:\directory1\directory2"
followed by the line:
drive C is mounted as local directory C:\directory1\directory2\
followed by the lines:
Z:\>C:
and:
C:\>named.bat
Which launches the program.

The program displays lines with the name of the program, copyright information.

This is followed by a line from DosBox stating "Drive+path not found: C:\directory1\directory2\
followed by:
C:>

Meaning that the program has terminated as soon as it tried to execute a command looking for the files in the 'not found' but mounted directory.

Why can't the directory be 'found' when it was just mounted (it was found to execute the batch file?)

BTW the batch file is as follows:

echo off
progname

Why doesn't the program find the mounted directory?

How to cure this (I cannot change the program code.)