your sheet is quite a mess very hard to make heads and tails of it..
since all the valid options start with a code like "R01 -" or simular you should create a table with in column 1 the codes, in column2 the text and col 3 the combined col1&2
then in the if you can use LEFT(A23,FIND("-",A23)-2) to find the code where the find function helps to catch both RO1 as RO10 the -2 avoids having space and - in the search text.
alternatively it is also worth considering building a table with a created combined searchkey of A23 and C23 to lookup the long text in a standardized table.
the outcome of above would be searchkey R01 -Basic so you should have a table that has all possible searchkeys with their applicatle text.
in both solutions you can keep the dropdownlists as is with the "R01 - long text" only for formula handling you use the referencetables