Finding float numbers

[Michael Gerbracht <smartmails@...>]

I need to convert float numbers into a string in a certain way[1]. The
original string looks like:

'var*4+5.2E-7-var2'

I need to convert it into:

'var*@"4"+@"5.2E-7"-var2'

so all floating point numbers n need to be replaces by @"n". Can you
suggest a good way to do that?

My main problem is to define a pattern for searching that matches all
floating point numbers, but not e.g. '4+5.2' in the above example.

Is it possible with lua or do I need the lpeg extension?

Thank you very much!
Michael

[1] I need to do that because I use RiscLua which supports floating point
numbers only as userdata.