Chemometric software´s have the option to export a matrix to a TXT file (in this case a constituents matrix), in a way we can import it easily into R, to work with. It is the first step to go into the R world.
I use in this case Win ISI Software, but sure you can do it with othersoftware´s as well.
See the video:
Exporting from Win ISI / Importing into R