Thanks for the screenshot.
Well, as I understand your scenario/ case a bit, I think you need to use Smart Markers for those dynamic columns (in the screenshot). You have data in rows under those static columns where as dynamic data would be filled for your dynamic columns from your data source. Now you want to retain your static data as it is (in the static columns) and dynamic data should be filled under dynamic columns in such a way that your existing data (in static columns) should not be messed up or deteriorated. If my understanding is right, you should use “noadd” parameter when placing your Smart Markers for your dynamic columns, e.g “&=Table1.Field1(noadd)”.
Please see the document for your reference on Smart Markers:
If you still have any confusion/issue, please create a simple console demo application (runnable). zip the project and provide us here, we will check it soon. Also attach your template file (input file containing smart markers) and output file. Please remove inter-dependencies for external database or data source and use dynamic dataset/datatables in code, so we could execute your project seamlessly. Moreover, attach a sample file with data as per your requirements (you may create the desired file manually in MS Excel). This will help us really to evaluate your issue precisely and to consequently figure it out soon.