#Connect to the active Workbook
excel <- comGetObject("Excel.Application")

#Set the active sheet
sheet <- comGetProperty(excel,"ActiveSheet")

#Set a specific sheet
sheet <- comGetProperty(excel,"Worksheets","WorksheetXY")

#Create a new Worksheet
comInvoke(comGetProperty(excel,"Worksheets"),"Add")

#Define a range in a defined sheet
range1 <- comGetProperty(sheet,"Range","A1","A20")

#Read out this range from Excel
val1 <- as.double(comGetProperty(range1,"Value"))

#Give back the results to Excel
comSetProperty(range1,"Value",val1)