Mask the zone you need.
Sample the color you need.
Paint over the zone... as needed :o)
There is potentially one problem you are facing...
A fluorescent color looks more "vivid" on a dark background. This image has a white background...
This is about perception, it is a psychological thing, not a technical limitation of Ps or any computer.
Paint a dark background and your color will be more "vivid".
Here I darkened the box itself. The orange is the exact same on all 3 images.
Note the difference, especially between image 2 and 3
As suggested by Joojaa, increase the chromatic contrast. I am removing the yellow cast from the box making it bluer, so the complementary color, the orange, looks more orange.
I must say, that the sampled orange can still be a heck more vivid. I am just using it as an example of why you did not achieve a fluorescent look.