[rumpleteazer]

To intercept pressing of filter button, you should use task-method on a form. The input parameter for this method is task-event id. Filter event id is 2837, but you should better use macro Task (#taskFilter).

Example:

public int task(int _p1)
{
#Task
int ret;

if(_p1 == #taskFilter)
{
// you code handling filter-event goes here
}
ret = super(_p1);

Return ret;
}