Mo. Rev. Stat. § 488.5342

When a prosecutor is unable to appear in court as provided in sections 56.110 and 56.120, the person appointed shall possess the same power as the proper officer would if he or she was present and shall receive a reasonable fee pursuant to the provisions of section 56.130 for each case prosecuted to be fixed by the court and to be taxed and paid as other costs in criminal cases.