There *should* be, but I'm not certain, haven't gone looking. Would be something like looking at the browser criteria of a click, but that's only available for 'visited web page' and 'click link', not on any of the email filters like clicked link in email. And since the 'bot' doing the clicking almost assuredly doesn't accept cookies, I would guess that it doesn't get past the tracking link server and on to the actual page result, but maybe... and then if you got something that far, what that browser agent string might look like is anything under the rainbow, pretty much... here's a couple of link checker user agent lists
http://www.user-agents.org/ http://www.infosyssec.com/infosyssec/security/useragentstrings.shtml just to give you an idea of what you're up against on this topic...