I was able to figure it out. Once I have an active sheet selected, I can then do
%get cell A1
getA1 = h.Activesheet.get('Range','A1');
%select cell A1
selA1 = getA1.Select;
%set cell A1 as the current cell
currentcell = h.Selection;
%apply ctrl-end and select that cell
currentcell.SpecialCells(11).Select % ctrl-end is special cells item 11
%get the address from the selected cell
selectedcell = strrep(h.Selection.Address,'$','');
%get the constructed range from ctrl-end to immitate ctrl-shift-end
getctrlshiftend = h.Activesheet.get('Range',['A1:' selectedcell]);
%select the cells as you would with ctrl-shift-end
selctrlshiftend = getctrlshiftend.Select;