Yeah creationists tend to accept microevolution, but say things like 'no dog ever became a cat' or something like that. In other words, they seem to accept within-species evolution, but don't accept that one species can become another species.
Obviously, that makes no sense scientifically, because 'species' is just an arbitrary name we give to things when we deem that the differences are sufficient to merit a new classification.
Once you accept a single DNA mutation, you've accepted the whole of biology and Darwin, there's no escaping it. Everything comes down to single-letter-changes piling up.