Use the conditional branch commands for when the key is pressed. In that conditional branch, code in like "If down is pressed, move cursor down" and so on. Use variables to keep track of what slot is highlighted. An example would be..So like if the cursor is on bag the variable would be 2, if save is highlighted its 5.
Then have a conditional branch for when enter is pressed. Check to see what slot is selected by using another conditional branch (again using the example- 5 would be save)- then code in what you what to happen for each slot.