Substituting letters - contextual alternates



I wonder if anyone can help

I am trying to substitute the normal 'i' letter to the dotlessi in specific combination of letters, especially Vi and Yi. For example when someone types Vi, I want the i to change to the dotlessi.

I know about contextual alts but this only changes the first letter.
sub a' [ a b c d f g h i j k l m n o p q r t u v w y ] by uniE002;

Is there any coding I should use to achieve this?