I would have sent a PM to you, but I see that feature is disabled.
Forget capos. Only the most embryonic, misinformed people use them on tenors and plectrums. Why? Because they are forever stuck in first position chord forms. That's a dead-end which has no future progress. Follow the link I'll provide. It will give you the proper direction towards learning the plectrum neck so you can confidently play anything you want with real freedom---and no capos. banjohangout.org/blog/34982
I'm a learner on a 4 string plectrum banjo, tuned cgbd. Where can I find a chart for capo use?
I'm not sure what a capo chart is, but I agree that you shouldn't be working with a capo on a plectrum banjo. The reason is that there's no good reason to use a capo.
If you're thinking about a capo because the frets seem too far apart for you to make some chord fingerings work, the answer is to temporarily modify those fingerings for your own use. Eventually you may find you can handle fingerings that once seemed impossible! And as someone else noted, once you start working your way up the neck with chord inversions, the frets are closer together anyway. Work instead on learning your chord figures, and how they can move up the neck (toward the bridge, that is).
The McNeil book that was suggested is good, but it may be a bit much for someone just starting out. If you look at any book of basic plectrum banjo chords (like the Mel Bay chord books), there's usually information at the end of the book about moving chords up the neck. Even that may seem like Greek to you at this point, but once you learn all the first-position chords (at the nut/peghead), it will start to make sense.
If you're thinking about a capo in order to transpose tunes into different keys, probably to accommodate your vocal range or somebody else's, then learn how to do that manually, it's really pretty simple. And the digital sheet music that's now available for download often can be transposed into any key right on your computer, along with the chord changes.
There may be some advantages to using a capo. But in addition to the disadvantages already noted by me and others, the main problem is that it also throws all of the position markers on your neck out of whack. So even if you know your chord fingerings, you can and will get lost on the fretboard in a hurry.