Possibility 1:
If the < or " item is not present in the 'viminfo' option then all
registers are saved on shutdown and restored at startup. If it is
present with value zero, then no registers are saved. If it is present
with a value >0 then at most that number of lines is saved for each
register.
See :help 'vi'
Possibility 2:
Most registers can be treated as string variables named @a, @b etc.
They can be read by including them in an expression. Most of them can
also be set by means of a :let statement. To do it at startup, put it
in your vimrc.
See:
:help :let-@
:help registers
:help expr-register
You can also put a register into your editfile, or delete or yank into
a register. I use the following mappings but of course they can also
be typed:
:map <F4> :$put +<CR>
:map <S-F4> :0put +<CR>
The above puts the clipboard linewise, after the last line for F4 or
before the first line for Shift-F4
See also:
:help y
:help d
:help p
:help P
:help :yank
:help :delete
:help :put
Best regards,
Tony.