Brute-Force Substring Extraction

In my product description field, I need to extract the data that looks like
19-3-19 or 0-0-7. Sometimes that pattern is in the data, sometimes not.
I only want those that contain the pattern, of course, but I have no other method of determining whether or not the pattern will be in the description.
I thought I'd found a method that worked, until I encountered descriptions
that had a '-' in it prior to the pattern.

Here's what I have so far, it works for all but the last one.

CREATE TABLE #TMPPROD (
PROD_DESC VARCHAR(60)
)
INSERT INTO #TMPPROD
SELECT '22-4-12 15%SCU'
UNION ALL
SELECT '14-4-8 W/F'
UNION ALL
SELECT 'UFLEXX 17-3-17 2%FE'
UNION ALL
SELECT 'FERT-PEST 19-19-19'

SELECT PROD_DESC, SUBSTRING(PROD_DESC,CHARINDEX('-', PROD_DESC)-CASE WHEN PATINDEX('[0-9]', SUBSTRING(PROD_DESC, CHARINDEX('-', PROD_DESC) - 2,1))<>0 THEN 2
WHEN PATINDEX('[0-9]', SUBSTRING(PROD_DESC, CHARINDEX('-', PROD_DESC) - 1,1))<>0 THEN 1
ELSE 0 END, CHARINDEX('-', SUBSTRING(PROD_DESC,
CHARINDEX('-',PROD_DESC)+1,2))+CASE WHEN PATINDEX('[0-9]', SUBSTRING(PROD_DESC, CHARINDEX('-', PROD_DESC) - 2,1))<>0 THEN 2
WHEN PATINDEX('[0-9]', SUBSTRING(PROD_DESC, CHARINDEX('-', PROD_DESC) - 1,1))<>0 THEN 1
ELSE 0 END+2+CASE WHEN PATINDEX('[0-9]', SUBSTRING(PROD_DESC, CHARINDEX('-', PROD_DESC) +1,2))<>0 THEN 2
WHEN PATINDEX('[0-9]', SUBSTRING(PROD_DESC, CHARINDEX('-', PROD_DESC) - 1,1))<>0 THEN 1
ELSE 0 END) AS 'ANALYSIS'
FROM #TMPPROD
WHERE PROD_DESC LIKE '%-[0-9]%-[0-9]%'

DROP TABLE #TMPPROD


Any pointers on what to try next, or have I severely over-complicated the process - as I am wont to do.

Thanks
Mark