I have the following statement which basically counts the number of telephone calls in a ranged (in sheet 2) based on cell 'D58'. This works perfectly.

=COUNTIF(Sheet2!L:L,D58)

I now need to add an IF statement or another COUNTIF statement to the formula so I can count the number of calls over 30 seconds. The length of the call is in Column N in Sheet 2.

I have no idea how to do this and would be grateful for any tips.