Is imprisonment considered an expiation for someone who has incurred a "hadd" punishment from Allah's prescribed penalties, such as fornicaton or theft, in countries where Sharia "hudud" are not implemented?

It is not permissible for a Muslim to accept man-made laws in place of Allah’s laws, because they are not equal in benefits and effects on the individual and society. The Prophet (peace and blessings of Allah be upon him) clarified that whoever dislikes it in his heart has been absolved, and whoever denounces it is safe, but whoever is pleased and follows it is not. These alternative punishments, such as imprisonment and the like, are not considered expiation for sins; rather, sincere repentance is the foremost means of expiation.