How to reference a DB with a period in its name ?

Hi:

I have a DB named "thedb", which has a schema called "theschem" which has a
table called "thetab". In a perl/DBI script, I am able to work with the
table by referencing it as... "thedb.theschem.thetab" as in... "delete from
thedb.theschem.thetab where col1=1"

No problem (so far...)

New DB now has a name "thedb.v1" (notice the "."), the schem and table are
the same as above. But now I'm getting a syntax error presumably because
of that "." introduced in the DB name.

I tried encapsulating the DB name in double quotes (no good), single quotes
(still no good) escaping with '\' (no good), escaping with ".." (no good).

Is there a way I can reference the DB which has the "." in it's name ?

v11.5 on linux (I know, way past time to upgrade)

Thanks in Advance !