As far as I can tell, there’s no way to pull apart a diction word to parse it, as you seemingly can in Inform:
A frequency is a kind of value. 100.9kHz specifies a frequency. 100.9 kHz specifies a frequency. 100.9 specifies a frequency with parts integer and decimal.
I wonder if it would be possible to split a dictionary word into multiple dictionary words, maybe something like
(split word $Word at @. into $FrequencyInt and $FrequencyDec), though that would still involve some way to verify that the two split parts were themselves numeric and in-range.
This is probably the one puzzle from Sand-dancer I’ll have to completely change.