dll for tradestation2000i

i require a dll, that calls live stock prices from tradestation2000i, and then calculates the correlation between 2 data series. The code in tradestation allows this, but unfortunately cannot accurately calculate more than 7 decimal places, the formula i made in excel works prefectly as it can do up to 30 decimal places. I am able to supply the excel spreadsheet, and also the easy language code for this formula. The "lookback period" i want for both data sets is to be a variable however, and I didnt know how to make this so, in my code. I require the code to lookback between 1-500 periods (bars). If anyone has any experience of this kind of software, then please inform me so I will offer you the job infront of someone who hasnt. the code has to have 5 arrays, 1st one has to collect x numbers of data1, 2nd one is x numbers of data2, 3rd is x numbers of data1 squared, 4th is x numbers of data2 squared, 5th is x numbers of data1*data2. once the arrays are full ( up to the required lookback amount, eg 20 days) then the following values need to be calculated. summation of last 20 data1, summation last 20 data2, summation of last 20 data1 sqaured, summation last 20 data2 sqaured, summation last 20 data1*data2. from these final numbers, a few simple lines of code can compute the correlation. As this is my first posting on this site, I am not fully aware which information is required, but i am told that power basic code is preferable for making dlls that work with tradestation2000i. I have some information on how to construct dlls which i will attempt to post here, if i cannot then i will email them to anyone who is interested. I guess it is best to make the arrays 500 cells in size and then adjust the amount of days of data that are used in the calculations. I require the dll to update on each new price change without any button pressing, so the event that makes it calculate IS a price change. Once the array is full of 500 values, then i should delete the oldest day and shift all cells along by one and then add then new day. so as to give a rolling value. Ok Mr Zimmerman, I have attached some zipped example dlls and notes, thanks for your response. ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Installation package that will install the software (in ready-to-run condition) on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform windows 98, windows 2000.