Write to Excel smart Service

I'm building a small PoC where i need to write to an Excel spreadsheet. i need to save my data in certain cells positions.
Everything i'm finding points me to use the Export dataStore to Excel Smart service and to specify those cells positions in the node input using the two
custom cell position / custom cell values.

My problem is i don't have a CDT to load from, this is a purely sync records PoC. do I really have to build a CDT structure to get this to work ?