just to make sure, redeclaring means putting something like:
global numbervar aVar;
at the top of each formula, right? If so, you are doing things correctly.
A don't know of a way to determine, programmatically, where the formula is, but if you place it in the group footer, that is where it will perform its work. Typically, if I am manually summing something, I tend to put my incrementing formula in the detail section (even if it is suppressed), then the display formula can go wherever it is needed (usually a group footer) and the reset formula can go where it is needed (usually a group header).
To debug formulas, I will display them on the report, typically I hide the results of the incrementing/resetting, this way I can verify if they are operating correctly.
HTH