Using textscan to read in 1 part of a txt file

Hi,

I'm trying to read in a specific part of a text file in numerical form.

The text file is called "0152_TrendData.txt"

The file contains a string of information written like this:

"Sample 152", "30/01/2012 16:28:41"

"P2","0.666774"

All I want from the output is say peak=0.666774

I've seen answers to textscan problems elsewhere but still unsure of the best way to do this.

Thanks for any help.

Damian