Bojan, I don't understand exactly what you're trying to do.  But it's very simple to add parameters dynamically to the parameter database, just use database.set(new Parameter("my-parameter"), "my-value")

It's exceedingly rare to need to do this though: in fact ECJ does it only once (for master-slave communication).  If you're thinking of setting parameters dynamically, you're almost certainly going down the wrong road.

Sean

On Jun 30, 2013, at 4:03 PM, Bojan Janisch wrote:

> I've search in the manual, but there was only a small part which describes the creation of parameters.
> Does someone got a simple example of how to get a specific parameter e.g. custom inputfolder at 
> evaluation of a GPTree?