Either way would be fine I think. Allowing a quoted identifier like it works for SQL Plus would probably be the best solution - Looking for the last @-symbol is probably the easier one.
Hi!
It is possible to start the plsqldev.exe with command line parameter to automatically log on to a database like this:
plsqldev.exe userid=TESTUSER01/password@DEV_DB
Unfortunately this does not work with passwords containing the @-symbol. When you e. g. have a command line like this...