i tested it.
i added links to onedrive through localhost, then started xlsx file through localhost., etc.
and due to security settings I got some messages from it - saying location may not be secure.
The strangest thing - I think the problem comes from here: \c$\Users\MyID\ .....
I think xl considers this as relative link, but does not send you to the root as one may expect. so it doesn't start with \\localshost.
But it adds the starting path of the xlsx file: so you end up with something like:
the %20 is no problem at all. it is totally standard and actually a must for most of the normal hyperlinks.
however, ..\..\..\..\c$ this works
the way I see it - the xlsx must be in the path of the hyperlinks, and then you can make them really relative, not starting from c$
This also should work (or with any other network address):
\\localhost\c$\Users\MyID\OneDrive%20-%20BRT%20Services,%20Inc\Documents%20-%20BRT_RMT\MAR\CURRENT\Recent@20Update%Plus%20Pending.pdf