Re:

=(len(A1)-len(substitute(A1;A2;"")))/len(A2)

The above solution works well.

I am looking to do something similar but count a number of text strings in a range of cells. What complicates the issue is that the text strings can have more than one occurrence on any cell, e.g., a cell could contain 'apple, banana, orange, apple, orange, apple' so the count for the string 'apple' should equal 3 from that cell and then be added to the total for all the cells in the required range.

I need to court all the instances of the string 'apple' in the cell range c1: d9842

I also need to count all the instances of 2 strings 'apple' and 'orange' as a combined total in the cell range c1:d9842