You can make it easier to help by sharing some additional info:
in reply to finding the field number of a matching pattern in perl
What is the source format of your data; a database, an html table, a doc table, a spreadsheet, a csv file?
- How are you making the data available to perl; slurping a file; reading line by line, db Row by Row or field by field?
Your my $data = "Region Item volume Month" if ($data1= .... makes me think you're trying to step thru an array where the elements (scalars) $data0,$data1, $data2 (etc) each contain the items you want and two more... (in which case the array after "my" needs an @ sigil rather than $). If that's in fact the case, have you mastered moving the data from its source to your script? And if so, then a for loop;split and (since your regex is borked, as noted above) perlretut should help.
What you've provided (as of this writing) just isn't enough to be sure these suggestions are on track. So please update your question (and mark the update ). And even pseudo-code benefits from using required elements like semi-colons.