What I changed was

DO pgmname parm1, parm2, @parm3

to

DO pgmname parm1, parrm2, parm3

In pgmnameI set parm3 and test the result in the calling program. It appears to work.

>>My problem was the @ in front of the field name. When I change @parm3 to parm3 in my do command it worked.
>>
>>Thanks to every one who help.
>
>If it was a field name, you'd have had that problem even in a function call. You can only pass by reference a variable, not a field.