Return value left of VLOOKUP column

=INDEX($col_return,MATCH($cell,$col_search,0))

Reverse text

=JOIN("",ARRAYFORMULA(MID($cell,LEN($cell)-ROW(INDIRECT("1:"&LEN($cell)))+1,1)))

Count number of certain character in cell

=LEN(REGEXREPLACE($cell,"[^char]",""))

Count number of certain character in range

=ARRAYFORMULA(SUM(LEN(REGEXREPLACE($range,"[^char]",""))))

Letter to Number

=COLUMN(INDIRECT($cell&"1"))