I want to "normalize" the price history of a stock to it's latest closing price.

I thought I could do it with

C / C0

but the C0 was decremented, day by day, same as the C, so all you get for an indicator is 1.000 all the way back to the begining of time, when all I expect is today's indicator value to be unity.

I tried        C / [C0]       and    C / {C0}      and     C / "C0"      but recieved an error in every case.

Isn't ther some way to treat today's closing price, or any indicator value on any day as though it were a constant?   Something like an absolute address vs. a relative address in a spreadsheet?   

C and C0 are the same thing. The 0 is an assumed parameter when it is missing.

You can fix a bar in TC2000 version 12.2 by using an actual date for the bars ago parameter.

C / C'08/09/2012'

But you will need to change the formula each day if you want to fix it to the most recent date.

This is actually a new feature in TC2000 version 12.2. In TC2000 version 7 the date is converted to an integer bars ago parameter that does not change as the Custom Indicator is calculated instead of being fixed to whatever date is used.

PCF Formula Descriptions
Handy PCF example formulas to help you learn the syntax of PCFs!

Can I get around changing every formula every day by the use of a global environmental constant or variable that I only need to change once a day?

No, you can't. That's why I pointed out that you couldn't in my original response. If there had been a workaround I would have mentioned it.

Sorry.

So now I like the way

 (  C / C'08/09/12'  ) 

levels the field in the present,  but I would further like to normalize the normal fluctuations of the market out of the picture with secondary normalization by a similarly normalized market index, perhaps something along these lines which leads to an immediate formula error

 ( C / C'08/09/12' )   /  ( DJ-30 / DJ-30'08/09/12' ) 

I do not know of a practical automated method of writing Relative Strength PCFs in either verison of TC2000 as the Personal Criteria Formula Language does not have syntax for referencing other symbols. You may wish to review the following for a semi-automated technique for creating Relative Strength in a PCF:

Indexes in PCF's
RSMA PCFs