How to create a user defined function in db2 in os390 machine

I was able to create a sclar user defined function but I need a function consisting of Sql statements

And a sample Jcl to execute the function

I'm able to execute external user defined function using spufi

I need the boby of the function and an example will be very helpful

and also the jcl

-- Uday Bhaskar (g_uday_1981@yahoo.com), November 19, 2004