Well, fair enough; your best resource would be to go to the documentation and/or web site for the particular piece of forum software you are running.
Here are a couple: www.phpbb.com, www.vbulletin.com (this site, for example, runs on vbulletin). PhpBB is a popular, free, forum. There are many others.
As to your exact question, I'd check out either the "Administrator" page, or the "config" file, but I don't know which; if you come back with the actual name of the software you run, someone (but probably not me) might have a little more info for you. But, as I mention, you'd probably find the right kind of expert at a forum devoted specifically to your particular brand of forum software.
Also, and just a thought: I dunno if forum developers have made allowances for "limiting" the power of the administrator. So, I don't know if what you're asking is possible; but, I will wish ya "good luck!"