Countif example.xlsx

Hello
Just wondering if someone can help me with the countif function?

I have uploaded an example of my spreadsheet. I'm trying to copy the countif formula, but am having the following problems:

As you can see, from C 50 (all the way down to C299) I need to input the countif function (it's covering/counting data from C2 - C46).
However, when I drag the formula down, from C50, the range is changed. Is there a way to drag the countif formula down from C50-C299 without changing the range (the range still needs to be C2-C46)?

Furthermore, as the formula is dragged down, I need the countif criteria to change. For example, C50 needs to be 1, C51 needs to be 2, and so on until number 250! Is there anyway this can be done other than manually changing each formula?

I'm going to need to apply this to 30 participants (30 columns), so that's 7,500 times I'm going to be needing to use the countif formula!

Thank you so much for any input!!