數字間加逗點 依數字數 (15250)

D2=IF(COLUMN(A1)>CEILING(LEN($B2)/$C2,1),"",RIGHT(LEFT($B2,(COLUMN(A1)-1)*$C2+(MOD(LEN($B2)-1,$C2)+1)),$C2)&REPT(",",COLUMN(A1)<CEILING(LEN($B2)/$C2,1))&E2)