how do you subset R data frame based on provided column names via a function argument? -

i trying create r function based on given data frame first argument, subset data frame based on provided arguments:

for example, df this:

date       server1 server2 server3 server4 1/1/2004     10     20       10      5 2/1/2014      4     4        4       20 3/2/2014      1     5        5       39 

i need subset df:

for example, if pass function(x, server1, server3, server4), this:

data<-function(x, ...) {  subset(x, select=c("server1","server3", "server4")) } 

but, argument list should not known. should apply data frames not knowing column names.

any ideas how accomplish in r?

if pass arguments strings should work fine this:

subset2<-function(x, ...) {   cols <- c(...)   subset(x, select=cols) }  subset2(dat, "server1", "server3", "server4") 

but i'm not sure why such wrapper necessary. perhaps missing true goal is?