DB2 has built-in encoding/decoding.
For OPs question, use....
select CAST(ColumnName as char(20) CCSID 37) as ColumnName from TableName where SomeConditionExists
http://www-01.ibm.com/support/knowledgecenter/SSEPEK_10.0.0/com.ibm.db2z10.doc.intro/src/tpc/db2z_introcodepage.dita