The future value function in Excel is detailed here: https://exceljet.net/excel-functions/excel-fv-function
Assuming the nominal interest rate is 2% per annum compounded monthly.
Future value after depositing $100 each month for 12 months.
=FV(rate, nper, pmt, [pv], [type])
This is the calculation the Excel function is doing.
n = 12
d = 100
r = 0.02/12
fv = d (1 + r)^1 + d (1 + r)^2 + ... + d (1 + r)^11 + d (1 + r)^12 = 1213.08
This can be converted to a formula.
which is equivalent to the one here: http://financeformulas.net/Future-Value-of-Annuity-Due.html
The phrase "calculated daily" means mid-month cash flows have the partial month interest accumulated correctly. However, the $100 cash flows in the question are monthly so mid-period cash flows are not relevant and the above method can be used, (albeit with equal length months).
Nevertheless a daily calculation can be made.
The following assumes the nominal interest rate is 2% per annum compounded daily. This is not quite the same as 2% per annum compounded monthly - ref., (but the difference to the result amounts only to 1 cent.)
Screenshot showing Excel formulas
It is unlikely you would require daily interest to be calculated on calendar months i.e. with unequal number of days per month. However, if you did require it there is no short Excel formula for it.