So, there is no DeriveKey in TMSCryptography-Pack, just the extract and expand without enough comment to not shoot yourself in foot.
HKDF is modern and well structured, but the input should have high entropy, in other words and input must be key or an equal to decent entropy of a key, also should not be used with short password or without salt and/or info.
KDF2 is different thing, if you need the closest thing to HKDF then use PBKDF2, and it seems
DEC doesn't have HKDF, but philipp.hofmann example should work, i think.
I can't run philipp.hofmann code because ... well.. SHA256 is only standardized in 2001, while my XE8 released 2015, may be SHA256 is not mature enough to be considered valuable addition to system.hash in 2015.