'coke' in Polish?

Since I think PIE *k^ etc. alternated *k/*c^ depending on the
succeeding sound (consonant/back vowel vs. front vowel) and that *kW
etc. alternated similarly *kW/k, while plain *k etc. did not
alternate, since all *k's were found in loans, I would like to know
how a real language with alternating dorsals would handle a loan.

Therefore:
How is eg. 'coke' (as in 'cocaine'; assuming it's a recent loanword in
Polish) inflected in all cases in Polish? Does the -k- alternate (eg.
with -c- ?) where it would in native Polish words?


Torsten