403 question

I’ve learned how to create custom error pages using .htacess. I’ve also noticed that certain areas of my website are 403 forbidden. For example, if i go to www.myweb.com/directory/ , and the directory i’m trying to access doesn’t have an index.htm page, i get a 403 error. I was wondering if there is any way i can duplicate this effect on other pages of my website; ie. is there any way to make it so when i try to get to www.myweb.com/directory/forbidden.htm , i get a 403 page?