The OP vs the First Price

Is anyone aware of a software (charting) package which allows the user to set the opening price of an equity for the first bar of the day for ANY tick or time frame equal to the "generally agreed upon OP" (or does this by default)? My reason for asking has to do with the fact that I have found that depending on the data feed one uses, the First Price of the day is highly variable and thus if the charting software that you use "decides" that that price should be the Open for your very first tick or time bar of the day (RTH), the OHLC stick or the candle that is generated can be different from what someone else with a different data feed gets.
Clearly the Open for ALL tick and time bars should be the same. Every tick and time bar will be affected by the choice of the first open. A way around this mess would be to have the software set the first open = the OP.
I don't think this is an arcane thought and do appreciate that even if the the first bar open was set = OP, if your data feed is the pits then it probably won't make much difference. If one poses this question to the data/software vendors (from IB to DTN to esignal) the response is rather underwhelming. Any input from any trader would be greatly appreciated.
TIA.
lj

eSignal deffo. Provides the functionality to edit any bar.

Many thanks Blade. I'll do the 30 day freebie with those boys.
Best.
lj

If regular trading hours (RTH) for US equities begin at 9:30:00 ET, then the Open price of the first 4 bar tic (or OHLC stick) for RTH MUST occur after 9:30:00? True or not true?

FWIW, I believe that this statement has to be true. No price prior to 9:30:00 should be present in that first candle or OHLC stick, i.e., ALL candle or OHLC stick charts whether they are tic or interval charts MUST use data which starts after 9:30:00.

If someone thinks this statement is wrong please destroy it but only if you can explain why it is wrong.

TIA

lj