How do I show page numbers in my TOC as A-1, A-2 etc for my one Appendix

My manual has only one Appendix. I have my pages numbered as A-1, A-2, A-3 etc. (A for Appendix). I cannot figure out how to get A-1, A-2, A-3 etc. to show up in my table of contents without doing it manually. How do I set up my paragraph designer? The only way I can figure it out is by calling my title Appendix A. But since I won't have an appendix B, C etc., I want to name it simply Appendix. Any help would be appreciated