UFT API refreshing the excel in runtime

I have a gui and then api test in test flow. Using excel as data source, the gui test fills up an application (storing it in database on saving) and then i get an OrderNo from the UI and save it in the same excel/ or another excel. Then a retrieval service (Rest getData service) starts and using the OrderNo from the saved excel sheet, it retrieves the data. However, When i see the datasource excel in the UFT, it is not updated at runtime of the api test so previously saved OrderNo does not pass to API test. I tried getting that OrderNo in several ways but does not work. What would be the best way to get that data for my apitest in the flow. In short, a variable OrderNo is generated in my gui test, i want to pass it to api test in runtime. How do i do it?