[R] regexpr virtue

[Petr PIKAL]

Hi all

I have got something like that (actually those are column names)

[51] "X19.2.300b...80"          "X19.2.400v...80" "X19.2.400b...80"  
"X19.2.300v...90"          "X19.2.300b...90" 
[56] "X19.2.400v...90"          "X19.2..400b..90" "X19.2.300v...100"  
"X19.2.300b...100"         "X19.2.400v...100" 

in character vector. I would like to get last n figures from this 
character vector but my regexpr unerstanding is inferior and I did not 
succeed. 
Please, is there anybody who can extract those n digits from end of each 
character string? If there were only 2 digits I could use substr but there 
can be one, two or three digits.

I tried several variations of

gsub("0:9$", "\\1" ,names(foto)[10])

but either got whole string or an error.

Best regards
Petr