Property 'defaultvalue' is readonly, use alter table

Agnes
>I am trying to temporarily reset the primary key field in a table to call 'nextcd' routine to bump primary key counter and return as default value when records are added.
>
>When running statement below, I get 'property is read only' error.
>
>dbsetprop('vendcontact.vendcntcd', 'field', 'defaultvalue',"nextcd('contact')")
>
>Any help would be much appreciated.
>
>Todd