Thanks again Hector. This time just went perfectly with the new
arrangement modified, as follow
=countif(c19:n19,"l")*7.5+sum(if(isnumber(--substitute(lower(c19:n19),"l",5)),--substitute(lower(c19:n19),"l",0)))
I'm expecting get better & set down ideas fluently for these kind of forum. TNX
[Q19] =countif(c19:n19,"l")*7.5+sum(if(isnumber(--substitute(lower(c19:n19),"l",0)),--substitute(lower(c19:n19),"l",0)))

or, from the beginning...

[Q3] =countif(c3:n3,"l")*7.5+sum(if(isnumber(--substitute(lower(c3:n3),"l",0)),--substitute(lower(c3:n3),"l",0)))

please, consider that only you have the TOTAL (possible) combinations of letters & numbers

as I said...
"please, revise and adapt/modify suggested array-formula in [R3] according other "expected" representation (letters & numbers)"
and...
"p.s. don't forget what you just learned in "Hints and Tips for New Posters" ;)"

regards,
hector.