MATCH(TRUE,EXACT($D$373:$D$826,"dd"),0) seems to work in a formula using,
MATCH(TRUE,AND(LEN(R9)=5,MID(R9,5,1)="y"),0) but this does not

trying the following idea, not quite working yet:

MATCH(TRUE,EXACT(AND(LEN($AY$373:$AY$1402)=5,MID( $AY$373:$AY$1402,5,1),"Y")),0)