The <attribute>
tag will not work since it only supports plain strings, not EL expressions.
<set>
should do the trick:
<set name="flowScope.caption" value="consultaDeutesHandler.filAriadna()" />
(Substitute requestScope, conversationScope, etc. for flowScope as appropriate.)
You can refer to this value later in the flow xml, and from your views. For a JSF example,
<div>#{caption}</div>
will ultimately contain the value returned from consultaDeutesHandler.filAriadna()