JFLAP Turing Machine

In JFLAP have multiple labels for a Turing machine transitions. One of these shortcuts allows you to jump if the current ribbon symbol is not the specified symbol. For example, transition! G, x; R basically says, "Take this jump if the current tape character is not g."

So far so good. But the transition I want is this! □, ~; R which basically says "Move right until the current character is an end-of-line (empty cell) character". The problem is, I can't figure out how to enter "! □".

JFLAP online documentation allows you to:

The first shortcut is that it is possible to use "!" character to convey the meaning of "any character but this character". For example, with respect to a transition (! A; x, R), if the head meets any character but "a", it will replace the character "x" and move to the right. To write the expression "! □", simply enter "1" as you enter the command.

How am I really doing what this last sentence is trying to explain?