[Tiki-users] Using {display name="tracker_field_xxx"} inside another PluginList control block

Hi everyone, sorry for bothering you so often :)

Is there a way of using {display name="tracker_field_xxx"} inside 
another PluginList Control Block, e.g. inside {trackerprefill ...}?

The fact is I need to show a button like the Plugin Tracker Prefill 
does, populating a value from a tracker item field.

I've tried using something like

{lIST()}
{filter ...}
{OUTPUT()}
{trackerprefill ... value={display name="tracker_field_xxx"}}
{OUTPUT}
{LIST}

but I couldn't come up with a working code. In fact, looking at the 
source code, the assigned value is just "{display...".

I've also tried using {button ..} even {display 
name="wikiplugin_trackerprefill" format="wikiplugin" ...} instead of 
{trackerprefill} but with no luck.

Is there a way to do this?

Thank you

Alessandro