in reply to Re^4: Editing just one column in a file
in thread Editing just one column in a file

Because $, is the character used when you give a list of values to the print statement, but you've used '.'s.

Ie. You're giving the print statement a single (concatenated) value, therefore the item separator is never used.

This might achieve your goal:

perl -lane '$,="\t"; print @F[0..4], "\t\t\t", @F[25..30]' file.txt

but "three blank columns" is a very nebulous concept.

Update: FTR, I might code that as:

print join "\t", @F[0..4], ('')x3, @F[25..30];

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.

The start of some sanity?