WinForm Application "iWclockUp" to Upload Excel Data to clockodo time tracking with REST-API

Want a winform app where user can enter/select excel file as well as a mapping. A mapping refers excel column to clockodo field. For proper upload with the REST-API there is needed IDs for certain fields, depending on the mapping. The IDs can be retrieved with other REST-API Before upload any record all entries must be checked for correct IDs and other correct data. Only if all data is correct, the upload can be done. REST-API documentation: from [login to view URL] => Sample "FixCustProj" User must select Customer and Project from Combo Blank lines can be ignored The descriptional text is always at next line to the data line Ignore the line with "Endsumme" Col 1: Employee Col 2: Date Col 3: Time from Col 4: Time to Col 5: Break in min Col 7: h Col 8: Time Traveling Col 9: km travelled Col 10: expenses Col 11: comments to expenses POST entries with customers_id => user selects services_id => "Consulting" for normal entry, "Travelling" for travel col 8, "Car used" for col 9 entries, "Expenses" if col 10 billable => fix "1" users_id => id of employee col 1 duration => col 7 (h), needs to translated to sec, only for normal entry lumpSum => col 10 projects_id => user selects text => normal entry: taken from next line col 2, expenses: col 11 time_since => col 3 time_until => col 4 => Sample "FixCust" User must select Customer from Combo Blank lines can be ignored Ignore the line with "Summe" Col 1: Employee Col 2: Date Col 3: h Col 4: Project Col 5: Text Col 6: Travelling indicator Col 7: Hotel Col 8: Info POST entries with customers_id => user selects services_id => "Consulting" for normal entry, "Travelling" for travel col 6, "Expenses" if col 7 billable => fix "1" users_id => id of employee col 1 duration => col 3 (h), needs to translated to sec, only for normal entry lumpSum => col 7 projects_id => id of project col 4 text => normal entry: taken from next line col 8, expenses: "Hotel"