As far as I know, this cannot be done. According to Wikipedia, when you translate language A to language B, Google's procedure generally is:
Translate language A to English. (This is redundant if A is English, but technically still true.)
Translate English to language B. (Same note as above.)
(I cannot find documentation for this on Google itself, but this is also noted in a paper on machine translation by Boitet et al.) This explains why the T/V distinction is often omitted, even when language B also observes it, since there is none in modern English.
There are also some cases where the translation is first to a third language (so language A to language C, which is preset, to English to language B). The third language and the original may be close enough that there is a preservation of T/V distinctions (going from A to C), but one might still expect the omission of the T/V distinction to come up once English or language B is added.