"Toho" is the genitive form of "ten" (the, that), and also the accusative form for masculine animate nouns. It is "(tam)toho" in this sentence, because "that boy" is the direct object of the verb, and so in the accusative case.
"To" (the, that, and sometimes this) is both nominative and accusative for neuter nouns. You would use "(tam)to" if, for example, the object in this sentence were "auto" instead of "hoch."
Not sure I've quite answered your question, but maybe there's something useful in there!
Silly question but from your reply it would seem you could use either tamtoho or toho...correct? are they interchangeable?
Yes, both toho and tamtoho are accepted. I'm native AmE, but it's my understanding that they are more or less interchangeable. One of the CZ natives on the team may weigh in if there is any significant difference between them.
You could, if you wanted, say that there might be a difference similar to there and over there in there, bit I would not bother.
It should recognize/recognise British spelling automatically on the system level... The reality is not always such though... Which means we might need to manually add it but we are talking thousands of words.... Did it tell you it was just a typo or an error?