ah.....I get you now.

have you tried using env variables?

actually that don't work either, I've just tried. I even managed to kill SQLplus

windowsXP (my laptop) - oracle 8.1.7.0.
1. create 2 directories - one with a long dir name and one short.
2. log into SQLplus and verify that you can run a script in the short dir and that one in the long dir name fails.
3. exit and set some environment variables with the pathnames for the 2 directories (eg %LONG% and %SHORT%).
4. back into SQLplus and try running the same files but use the variables.
i.e.
>@\test\%SHORT%\test.sql and
>@\test\%LONG%\test.sql

the short one should work but the long doesn't even return the "maximum size is 79 characters." error but bombs SQLplus.

completely pointless experiment but at least it distracted me for a while

you could navigate upto the dir you what so the string is less that the 79 character limit (eg >$cd \bla\nearly_there\bla) . ugly but it'll work