how to pass a sequence name to a stored procedure?

I've created a stored procedure where we want to determine the currval of a sequence. The sequence name self is not known in front, so it has to be passed to the procedure. This, off course, can be done by a IN parameter. But how can i use it within the stored procedure correctly in a SQL statement. Like "Select schema.sequencename.currval from dummy"

I've placed schema.sequencename in a parameter (with the name SEQ_NAME) and tried next:

SEQ_CURR := SEQ_NAME || '.CURRVAL';

SELECT :SEQ_CURR INTO CURR FROM DUMMY;

The schema and sequence name must be dynamic but it doesn't work. Who can give me the working trick?