You only use (will) one time so you can take that out.
I will have ha (watashi ha suru koto owari) no imi
By the time ha (... made no shimashita) no imi
My room cleaned (heya no soji shimashita) no imi
Dakara I will have (nani?) my room cleaned (itsu?) by the time you get back.
You are very welcome. Very=more than (shinzen no eigo ha ooi hitobito ha more than welcome wo tsukaimasu.
Thank you so much !!