User-Defined Variables

Hi,

Is there a quick solution to implementing user-defined variables in PostgreSQL as they are used in MySQL?

I have the following MySQL script which i want to implement in Postgres
(NOTE : all ` have been changed to " for Postgres use):

SET @OTHER_CONCEPT_ID = (SELECT "concept_id" FROM "concept_name" where name = 'MRO' LIMIT 1);

Thanks,
Daniel.