Remove non-numeric characters from column

[jerrylshen]

I have a SiteNumber column in my Mylib.sheet2 spreadsheet that has a mixed fields of "Site 999", "Site 998", and "999".   

I want to remove everything except for the number aspect, such as 999 and 998.

I have tried this, but it gives me syntax error and symbol is not recognized error for the '[0-9]+' part:  

PROC SQL;
SELECT substring(sitenumber from '[0-9]+')
FROM Mylib.sheet2;

QUIT;     

Thanks

[Shemp · Accepted solution]

Substitute this for the substring function:

prxchange('s/[^\d]//', -1, sitenumber)