当找不到string时返回原始值

D列是C列的LOOKUP结果

ABCD 1 1234 1234567 Person1 ASKXXXXXXXX 2 3692 8465837 Person2 AFTXXXX 3 4789 7846199 Person3 AHY 

如果有8个,用B代替D中的X
如果有4X,用A代替D中的X,我用这个公式

 =IF(SEARCH("XXXXXXXX",D2),SUBSTITUTE(D2,"XXXXXXXX",$B$2),IF(SEARCH("XXXX",D2),SUBSTITUTE(D2,"XXXX",$A$2),"")) 

但是,如果没有“XXXXXXXX”和“XXXX”(第4行)

使用IFERROR(value, value_if_error)

 =IFERROR(IF(SEARCH("XXXXXXXX",D2),SUBSTITUTE(D2,"XXXXXXXX",$‌​B$2),IF(SEARCH("XXXX‌​",D2),SUBSTITUTE(D2,‌​"XXXX",$A$2),"")),D2‌​)