So to preface this, I live in Africa and bought an inexpensive banjo here and as such, it had no railroad spikes installed and there’s nowhere to get them installed. In th past whenever I have learned a song with capo if it was second fret I would tune the fifth string, always nervous it would snap, and if the capo was higher I would tune the fifth string alternately e.g. open for third and fifth, half step down for fourth etc. Now I just discovered a solution and that is to take a lego technic 3length cross axle 
and stick it under the string with the string running through a vshaped section and the end of the lego sitting on the fret I had a picture but couldn’t upload it I might try again. You can find the piece here https://www.lego.com/en-us/service/replacementparts
Fifth string capo solution
like this
That’s a clever idea, and very simple! I’ll have to borrow one of those from my son and give it a try. So far, I’ve not invested in anything more than making one from the cap of an ink pen like I saw on this video:
@BanjoBen has a neat little fifth string capo in the General Store
https://store.banjobenclark.com/collections/capos/products/strum-hollow-5th-string-capo
Thanks for the link Archie! I’ll be placing an order soon. 
I’ve seen that strum holler capo and considered getting one but I live in africa like I previously mentioned and the postal system is dodgy at best so this is all I’ve got
Hi @K_G I understand, the postal service here in the UK is a little dodgy too since it was privatised. They may still call it the Royal Mail but it is nowhere near as reliable and their costs are way much higher.