Here you'll find some tricks about Excel. = Some smart formulas= == Find case with a character (or a series)== Let's assume you have a column filled with e-mail addresses and other pieces of information. You want to sort only the e-mail addresses. The function FIND return a #VALUE error > =IF(FIND("@";A1)<>"#VALUE";A1;"") So using IFERROR we can retrieve only the case with @ > =IFERROR(IF(FIND("@";A1);A1;"");"") == you have two lists , you want to eliminate "doublon" == =IF( COUNTIFS( $C$1:$C$28;A1)> 0; "";A1) list of "already done" Column C , fom 1 to 28. list of "all" , Colum A use COUNTIFS, if > 0 , exist in the lsit "already done" !