How to call Excel UDF (*.XLL) function from R
I've got some Excel UDF functions written in C and compiled to XLL add-in file. Function itself is a data-subscription service (retrieves data according to request parameters)
Is it possible to call those XLL defined functions from R?
I think the very short answer is Not a chance. The reason being is that you need the Visual Studio stack for Excel, that very stack does not mesh with R. We do have Rcpp FAQ 2.9 on this.
The longer answer is that you have working C code. You can add that to R in a package. Rcpp can help.