I need a regex genius for casefixing...

If possible I would like to have a list of words lower case unless at the beginning of a field OR if it is after a colon symbol. These words are:
a
an
and
as
at
by
if
in
of
on
the
to
with

Right now all my Artist, Album and Title tags have the first word capitalized. In many instances I manually edited tags to keep acronyms like NYC, LAX, MC, DJ, or tripTYCH uppercase. There are also some instances where periods are present like "S.T.A.R.S." or "N.E.R.D." I would like to preserve these variations while preforming the original action at the beginning of my post.

Is it possible to have the expression ignore words with two or more letters capitalized whether a period is present or not? This would typically be considered a mistake and 'fixed' which I do not want to happen. If anyone can help me out I would be grateful.

I know it a complicated request, I just thought I'd ask as I began reading the regular expressions web pages and quickly got confused. Thanks for reading.

If you have already got that list then a simple search&replace with a separate action for each word and field would do the trick.
If you also ticked "word only" and "case sensitive" then the hits would probably be around 100%.
You could summarize all actions in a longish action group.

I think that a "regular" expression is pointless as there is no "regularity" but only individuality.

Thanks. Am I missing something though? Under actions I do not have search and replace only replace with regular expression...

almost a hit: there is also a simple replace (which implies a search as you have to enter a search string)
Sorry that I cannot help you a regular expression but language is not regular.

You may try out the different features of the $caps(), $caps2(), $caps3() functions.

DD.20100223.2310.CET