民國年 改月日二位數 (14109)

B2=SUBSTITUTE(TEXT("R"&SUBSTITUTE(A2,".","-"),"e/mm/dd"),"R-","民國前")

無民國前日期 C2=SUBSTITUTE("R"&A2,".","/")*1

C2=LEFT(A2,FIND(".",A2)-1)+1911&SUBSTITUTE(MID(A2,FIND(".",A2),9),".","/")