Using Aquila's 5th's tuning strings (ie: tuned like a mandolin or violin) the top string on a soprano ukulele tunes E, an octave above the "normal" second string tuning. Working down from that, it should be easy enough to find a combination of strings to give you almost any tuning you need.
For reference, that top E Aquila measures 0.015" under tension, about the same as 15lb nylon monofilament fishing line. NB: fluorocarbon lines tend to be thicker, per weight-rating. Unfortunately I don't have a range to measure.
Assuming you're tuning in "standard" ukulele intervals, your new (re-entrant) tuning would be dGBE, like a guitar, but an octave higher. A "standard" ukulele top string will go to B no problem, your G string is already covered by the normal 4th string in a set of re-entrant ukulele strings, which just leaves the re-entrant d ... I bet a standard ukulele 2nd string would be OK tuned down two frets, else a standard 3rd string will tune up to D ... job done
As always, YMMV, but, in the first instance, for the cost of a set of standard strings and a scrounged length of fishing line (if you don't have any to hand yourself), it's got to be worth a try
You'll not do any damage to a standard soprano ukulele with these suggestions. The overall string tension will likely be less than with a standard set of strings.
If you've got a slotted bridge and are worried about tying a big enough knot on the thin string, tie the end of the thin line together with a short length of thicker string to make a more substantial knot
Good luck !