Determine the RAL color numbers for each color used. Most programs will tell present this information to you in the color selection window.
Locate the RAL number on a RAL to Pantone conversion table. A RAL to Pantone conversion table or chart. An array of such conversion tables or charts may be found by searching online sources or at art supply or hardware stores.
Choose the corresponding Pantone number.
Exchange the RAL numbers for the corresponding Pantone numbers in the program you are using.