How to insert spaces up to column X to line up things in columns?

Question

I have my source code for copy operators written as follows.

foo = rhs.foo;
foobar = rhs.foobar;
bar = rhs.bar;
toto = rhs.toto;

I\'d like

Answer 1

I know this is old but I thought @talklittle had the right idea, the answer just got verbose. A quicker way is to insert spaces after the = and then remove all spaces after the 10th column like this:

   :1,4 s/^\(.*=\) *\(.*\)$/\1                           \2/
   :1,4 s/^\(.\{10\}\) *\(.*\)$/\1\2/