DB2 Net Search Extender supports the data type DATALINK.
db2 INSERT into db2ext.proxyinformation values ('hostname', '80' 'proxy', 10)
Note that only one row is allowed in this table. A trigger assures this.
The Data Link UDF returns blob (100 KB). To change the return size, use DB2EXTDL and update the database manager configuration parameter, java_heap_sz.