A similar discussion with accepted solution:
Programatically selecting cells in a uitable - MATLAB Answers - MATLAB Central
How to select/highlight a cell/row in the uitable programmatically? - MATLAB Answers - MATLAB Central
% m = numeric handle to uitable
m = uitable(...);
jUIScrollPane = findjobj(m);
jUITable = jUIScrollPane.getViewport.getView;
jUITable.changeSelection(row-1,col-1, false, false);
% subtract 1 from row and col you want selected
% the last two arguments do the following:
% false, false: Clear the previous selection and ensure the
% new cell is selected.
% false, true: Extend the previous selection (select a range of cells).
% true, false: Toggle selection
% true, true: Apply the selection state of the anchor to all cells
% between it and the specified cell.