Convert SPL to XLS

Unfortunately, we do not know about any possible spl to xls conversion at this time or what it might represent, but it seems to be related to some kind of export to Excel, but the source format is most likely a typo. Generally speaking, this is typically doable for various spreadsheets or structured data.

Simply put, it is impossible to convert SPL to XLS directly.
Thus, there is no so-called spl to xls converter or a free online .spl to .xls converter to be found.