I have: 哪里呀,我也是没办法,摸着石头过河罢了!
Is 摸着石头过河
'tapping in the dark'?
No, I don't know how, I'm still tapping in the dark.
I don't know about the phrase "tapping in the dark" because my limited English.
But 摸着石头过河 basically means try to do something via trials and errors. So my translation would be:
No, I have no idea, I'm still learning while doing it/I'm just trying to do what I can.
The literal translation of this idiom is something along the lines of, "feeling stones while crossing a river":
Figuratively, what it means is "to figure things out as you go along", as if you were wading through a river by feeling the stones on the riverbed with your feet.
To give an example, my understanding is that this phrase was often used to describe the economic policy of Dèng Xiǎopíng (邓小平), who was the leader of China after the death of Máo Zédōng (毛泽东). He used it to describe the sort of experimental, gradual reforms that brought China to the economic position it's in today.
Your phrase (哪里呀,我也是没办法,摸着石头过河罢了) is a bit difficult to translate without context, but it seems to mean something like, "There's nothing I can do about it either, I'm just figuring things out as I go along, that's all."