Extracting float from string

[Spencer Ernest Doidge]

>From a previous post,
I got many good solutions to extracting an int from
'X= 445 A'.

Now what about this one?
Somewhere (we don't know where) in this input string, we expect to find a float:
':X=  0.22456  A'

How can I suck the float out of this one?


-- 
Spencer Doidge