Dynamic filling of Grid Combo

Hi,

Iam searching for an good possibility to select an option from an huge list.
Since its an OSS Project, i dont use the Pro Version.
Normally i would like to fill an Combo dynamically, but i dont find an solution for that without the Pro Version.

Is there an Way to show an Grid or Listview below the Column and integrate it with the Cell Key Events ?
Or has someone an simelar solution to do something like that ?