MySQL function - TextToNumber

I need a MySQL function to convert text to a number, for comparison purposes. There are 7 format types: 1. Number - Already a number, so don't need to do anything 2. Detection - {"Not detected","ND"}=0, {"Detected"}=1 3. Count - Anything beginning with "<" divide by 10, anything beginning with ">" multiply by 10. e.g. "<10"=1, ">1000"=10000 4. Abs/Pres - {"Abs","Absent"}=0, {"Pres","Present"}=1 5. Letter - AA=0, A=1, B=2, C=3, etc 6. Pass/Fail - "Fail"=0, {"Pass","Pass 1"}=1, "Pass 2"=2, etc 7. Typ/Atyp - {"Typ","Typical"}=0, {"Atyp","Atypical"}=1 This will allow me to select data from my table using a WHERE clause, and specify a range. Example: Select result From results Where result > 0 And result < 100; If the result value is ">1", the select query will return this result (will evaluate to 10 based on rules above). The function should be case insensitive e.g. "ABS"=="Absent" and return a pure integer with no commas. Some of the results (especially format 1) have numbers after the decimal point.