Strategy testing with Candles from csv file

We want to perform strategy backtesting on history data stored in txt file. As we understand from the samples, the txt file should be converted to S# format before we can run strategy and testing on them. Please update if this understanding is correct.

We need sample code how we can covert txt file to S# format through code. What are the classes we should look at?

Or alternatively, can we run strategy on history data stored in txt file directly? Please share sample code if this is possible.

Regards
Shubha