Reg file/s compare & and output diff

HI,
Just wondering if anyone knows of a freeware registry editor and app that can:
(other than editing .reg files also:
compare 2 .reg files with options to:
Select the differences in either file and output a selection to a new .reg file.
(I.e in such a way that these differences could be then easily inserted into the system registry by way of this new .reg file)

P.S i have just browsed the web and installed about 10 reg apps and the ones that look promising are either too complicated, don't install or require you to purchase them.

PPs i already tried comparing 2 reg files with regshot etc and then manually editing but somehow managed to maul the edited file

Thanks

Ideally i think I would like to see an app that does this specifically.
i.E it would show the 2 files in different panes with different colors for Added, missing, keys + entries and also separate colors for modified ones.....
I.e you could have little palettes/legends down the bottom of each window showing the different highlight colors and you could click on these icons to select/unselect all these different areas across the whole file ETC....

Then I would like to be able to select keys from either file by color and merge and output the selection to a new .reg file.

I like the "big list" interface (not the reg tree) and also i think little tick boxes next to each entry/key etc would be cool... this way it would present like one of those taged html editors ETC and you could quickly select keys etc by ticking boxes then delete, invert selection, cut & paste or copy to other side ETC...

Also i think other than this, even a "one click" option to automatically find all the Registry entries that are new or changed (in the second window Vs the first) and output them to a new reg file would be cool.

perhaps some kind coder can modify an existing open source reg app to accomodate this cool functionality?