It's probably not a great idea, although they might not be a terrible option as pit wheels (where the choice is finishing in less-than-ideal conditions or DNFing). The Equipes I've seen have fairly low spoke counts (20 or 24) and are narrow by contemporary road wheel standards (19mm). There's no reason to go with such low spoke counts for CX even if you're pretty small, and as Zippy The Pinhead mentions, the spokes are nonstandard. (IME, almost everything about midrange and lower-end Mavic wheels is unnecessarily difficult to service, though.)
Mavic claims you can mount a 32mm tire on these rims but the sidewalls will stick so far out from the edges of the rim that you'll have a crummy contact patch and will need to run awfully high pressures to avoid pinch flatting.
The good news is that you can probably sell these Equipes (if you have no other use for them and they're in good shape) for $300 and then get a set of decent CX wheels built up with Major Tom rims, midrange hubs, and all-around tires for around $500.