Notice that the semi-colon must be escaped (in this case, with a backslash) because the shell normally treats the semi-colon as a special character. Thus for both the -exec and -ok options in gnome-find, one simply needs to enter the following in the text entry field:
The proper way to do something such as this is to specify a shell script to execute which will do the renaming.
This is the nature of the rm command. In order for it not prompt and delete the file, rm -f needs to be specified.