Probably a simple question about  strings

Hi,
instead of saving 5 strings to a SD card with a dedicated command like

SD.print("hola.txt",(floatToString(test, M, 4, 7)));
SD.print("hola.txt",",");
SD.print("hola.txt",(floatToString(test, N, 4, 7)));
SD.print("hola.txt",",");
SD.println("hola.txt",(floatToString(test, O, 4, 7)));

I would like send the data in one step. So I want to put those five strings together in one string only.

How can I do that?

strcat