With the Measure tool selected, click on a measure to bring up the Measure Attributes panel. In the "Barline:" item, you want to be able to choose a "Custom" shape for the half-bar, which you will create using the "Select" button (or just clicking on "Custom"), which brings up a "Shape Selection" panel. Since a half-bar isn't there by default, you want to click "Create" and make your own. Click on the "ShapeDesigner" menu (it's to the right of the "Edit" menu) and make sure that the "Line Style" is set to "Solid" (as opposed to "Dashed"), and set the "Line Thickness" to "Hairline". Now, click the Line tool button (it's the 4th button and looks like a diagonal line). Draw a vertical line from the second staff line to the 4th staff line to get the half-bar line (use Shift while drawing to keep the line vertical). You can click "Edit" to redo if you don't like the result, and you can use the Selection tool (the button with the arrow) to reposition your shape. Once done, click "OK" and your half-bar will be at the end of the selection options (something like no. 70). Click that and now "Custom" will end a measure with a half-bar. If you need more help or want to experiment, just click on "Help" in the Shape Selection panel or the Shape Designer panel (reading the help info is quite useful).