DrAxeman, In your previous post: Pre-process csv files before using, I replied with an inplace edit code. In that I use something called $. which keeps track of the current line number processed. So if you really want to do conversion of some sort then you can check for  $. != 1 and then apply the conversion for the rest of the code.

update: As graff pointed you shouldn't need the conversion function. Take this code for example

perl -e'$val = 9e-05; print "value = ", $val*2, $/;'
__END__
value = 0.00018
[download]

If you find the command line version of the program confusing just focus on the pieces after -e'. Everything is a regular perl code. I am just assingning a value using scientific notation and use it in regular airthmetic and get expexted results. Unless you are doing something fancy with your conversion i wouldn't go for a module

-SK