According to the Theravada Bhikkhu Patimokkha (quoted below), lay stewards of the monks or nuns should handle money, to my understanding.
If needed, exceptions or modifications to minor monastic rules can be made, based on The Great Standards. And not to forget "If it is desired, Ananda, the Sangha may, when I am gone, abolish the lesser and minor rules". (DN 16)
Rule 10: In case a king, a royal official, a brahman,
or a householder sends a
robe fund for the sake of a bhikkhu via a messenger, (saying,) "Having
purchased a robe with this robe fund, clothe the bhikkhu named
so-and-so with a robe": If the messenger, approaching the bhikkhu,
should say, "This is a robe fund being delivered for the sake of the
venerable one. May the venerable one accept this robe fund," then the
bhikkhu is to tell the messenger: "We do not accept robe funds, my
friend. We accept robes (robe-cloth) as are proper according to
If the messenger should say to the bhikkhu, "Does the venerable one
have a steward?" then, bhikkhus, if the bhikkhu desires a robe, he may
indicate a steward — either a monastery attendant or a lay follower —
(saying,) "That, my friend, is the bhikkhus' steward."
If the messenger, having instructed the steward and going to the
bhikkhu, should say, "I have instructed the steward the venerable one
indicated. May the venerable one go (to him) and he will clothe you
with a robe in season," then the bhikkhu, desiring a robe and
approaching the steward, may prompt and remind him two or three times,
"I have need of a robe." Should (the steward) produce the robe after
being prompted and reminded two or three times, that is good. .....
Rule 18: Should any bhikkhu accept gold and silver, or have it
accepted, or consent to its being deposited (near him), it is to be
forfeited and confessed.
Rule 19: Should any bhikkhu engage in various types of monetary
exchange, it (the income) is to be forfeited and confessed.
Rule 20: Should any bhikkhu engage in various types of trade, it (the
article obtained) is to be forfeited and confessed.
(Bhikkhu Pāṭimokkha, translated by Ven. Thanissaro)