It occurs to me that Sum & Range group of functions - and perhaps others - would be even better supported by the Beanshell builder if the parameter list were selected in the definition window rather than the function list.
e.g. this list
might instead show as:
SumLocation(…)
CountLocation()
CountLocation(…)
and then in a window such as,
there could be a further selection field - maybe a dropdown - to select the actual form of the function required. A default set of parameters would be presented and then varied according to user selecting a different form in the dropdown list. Ideally, the window would retain input that had been deselected between different format options being selected/deselected.
Mark