Miscellaneous topics that do not fit into specific categories.
Hi! If the file extension is .RCTDT, it’s not a standard Excel format, so conversion depends on which app generated the export. First, try opening it in Notepad, if you can read column-like text (commas/tabs/semicolons), rename a copy to .CSV or .TXT and import it in Excel via Data > From Text/CSV (choose the correct delimiter).
If it’s unreadable “binary” text, Excel won’t be able to parse it directly. Check the file’s Properties > Details (sometimes lists the originating program) or open the file in a text editor and look at the first line for a vendor/app name, then re-export from that original software as CSV/XLSX.