I want to paste variables in the logical expression that I am using to subset data, but the subset function does not see them as column names when pasted (either with ot without quotes).

I have a dataframe with columns named col1, col2 etc. I want to subset for the rows in which colx < 0.05

This DOES work:

subsetdata<-subset(dataframe, col1<0.05)

subsetdata<-subset(dataframe, col2<0.05)

This does NOT work:

for (k in 1:2){
subsetdata<-subset(dataframe, paste("col",k,sep="")<0.05)
}

for (k in 1:2){
subsetdata<-subset(dataframe, noquote(paste("col",k,sep=""))<0.05)
}

I can't find the answer; any suggestions?