そもそも置き換える意味がなくないか
https://i.imgur.com/ZAuSaoz.png

=
(
INDEX(B:B,MATCH("w",A:A,0))*
INDEX(B:B,MATCH("h",A:A,0))
)+
INDEX(B:B,MATCH("t",A:A,0))-
INDEX(B:B,MATCH("m",A:A,0))