Hi,
This will account for up to 500 dots:
=MATCH(1,-FIND(REPT("•",ROW($1:$500)),A1))
committed as an array formula**.
Amend the 500 if required.
Regards
**Array formulas are not entered in the same way as 'standard' formulas. Instead of pressing just ENTER, you first hold down CTRL and SHIFT, and only then press ENTER. If you've done it correctly, you'll notice Excel puts curly brackets {} around the formula (though do not attempt to manually insert these yourself).