I hope you can help. I am developing an application in C++ builder 5.0 that requires non-linear curve fitting. The excel solve function performs this operation. So from my application I want to puts numbers into an excel spreadsheet, run the solves function and read the results back out into my application. I have been looking at some of the stuff written here, and being relativity new to all this OLE, DDE and Automation stuff am finding it a bit confusing. Again hope you can help!