Fellow Monks!
I need your wisdom in the world of regular expressions.
What I want to do is this. Out of the following string:

#total mean for 530.2 nm = 411.67 W/m**2, dev= 0.2%

I need to extract the highlighted numeric value only.
Although I am, in this instance looking for a quick and efficient solution to this scenario, I would like to learn more. So... if anyone has an excellent link to a simple yet powerful regex tutorial I would greatly appreciate it.
And.... no, this is definitely not homework. Thank you in advance for your wisdom, for at the moment my knowledge of regexes is limited, soon I hope for it to grow.

In reply to regexp help needed by Anonymous Monk

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