Extending the drop down box further

Morning,

As you can guess from the title I'm not really sure what this is even called. I have been given the attached spread sheet and need to extend it, so it can deal with far more students.

On the sheet called 'Student PLC' in the C1 cell you change the name of the student - this is currently 'Student 1"
On the sheet called IGCSE PLC I have added students all the way down to Student 199

I need to the C1 cell to be able to pull through any of the 199 students information through, rather than just stop at Student 23.

Any help will be gratefully appreciated.

Regards