When you are typing a post, above the box you type into is a link: Editing & Formatting Tips - That explains how to post code blocks which avoid the problem (among other benefits), as well as how to get a * outside of code blocks if it's needed.
That would rename the selected files to what's in the clipboard, without displaying any prompt first.
I'm not sure if there is a way to do what you want using inline rename, but you could have a small dialog box pop-up to let you edit the name, using {dlgstring|Enter name|{clip}} or similar.
Or, better, use {clip|cleanfilename} to make what's in the clipboard OK for filenames, i.e.
{dlgstring|Enter name|{clip|cleanfilename}}
(You can still run into problems with clipboard text containing }, which is allowed in filenames. A script could do this in a better way if expect that to be an issue.)