Can't get checkbox to go true from another userform

Hi everyone,
This may have been asked and answered before, I have searched but have yet to come up with anything and have spent a lot of time trying to figure this out on my own. What I am trying to do is develop a electronic visitors log in excel that has three statements visitors must read and accept before they can enter.

I have a userform with date/time, name etc, then the three buttons that open another user form with the statements for them to read and 2 command buttons (Accept and Decline), Accept takes them back to the log-in userform and Decline closes all forms.

The problem I am having is I can’t get the checkbox on the log-in form next to each statement to go true when the accept button is clicked for said statement. I would like to disable the checkbox on the visitorsignin form so the only way it goes true is from the statement form.

I hope I explained myself well enough for someone to understand what I’m trying to do, the code is not finished yet either, still waiting for signature pad to come in so I can paly with it and figure out how to incorporate it into the file.

Thanks in advance for any help given,

Martin