no. That would be double counting. In the US, the carb count on a
package includes fiber, so you subtract the fiber to find out how may
digestible carbs you would eat.

Adding a fiber capsule to a piece of bread would increase both the
carb count (calculated as digestible carbs plus fiber) and fiber
count, so, the digestible fiber would not change.

If you think about it, adding some cellulose capsule to bread does not
change how much bread you eat.

You should be getting your fiber from food. Any eating program that admits
you will have to spend extra money on supplements to get the nutrients you
need is a failure from the get-go IMHO.