Actually, a slightly easier to follow formula, the position is set by the division part of the formula
ones (see note below)
Excel Formula:
=SEARCH(MOD(INT(M2/1),10),"3489")
tens
Excel Formula:
=SEARCH(MOD(INT(M2/10),10),"3489")
hundreds
Excel Formula:
=SEARCH(MOD(INT(M2/100),10),"3489")
Note that INT and the division part are not necessary for the ones formula but I've left them in so that it is easier to follow. This one could be changed to
Excel Formula:
=SEARCH(MOD(M2,1),"3489")
and it would still work the same.