On https://www.makercase.com/#/basicbox make custom box with parameters and click on Download box plans. Don't forget to disable Panel Labels and save it as SVG or DXF. Import image to XCS.

I used: 50x50x50mm, Outside, 4mm material thickness, closed, finger joints

Making a ribbon pattern for engraving. The best is Insert one rectangle then right click → Move to another layer (color) and duplicate rectangle shape Copy → Paste. Don't forget to set all rectangles as Engrave type to view pattern.

Insert rectangle and place it in the middle on TOP piece of box. Don't forget to set H (height) as your material thickness with unlocked aspect ratio. Otherwise your ribbon piece will not fit.

I used 20mm width and 4mm height

Insert bell Shape with the ribbon on top. Insert rectangle and place it on bell like on picture. Select bell Shape and rectangle (not with circle from bell!) and Subtract.  

Enlarge bell circle so that circle is touching all walls on ribbon. Select Circle and Ribbon and Unite. Insert rectangle and place it under ribbon as holder. Don't forget that H (height) of this rectangle is material thickness! Select ribbon and rectangle and Unite. Insert Text.

Your present box with a ribbon is done. :-)

Now glue all pieces together with wood glue. Don't glue top piece with a ribbon if you want open present box. :-) 

I used 100%power/4mm/s speed and 1 pass with Air Assist ON for cutting, 55%power|70mm/s speed with Air Assist ON for engraving.