Loop over non-standard variable names in R - r

Question

I have a dataframe (df) with variables that look similar to vector-variables:
myvariable[1], myvariable[2] , myvariable[3] , etc.
However, if I want to refer to them, R automatically creates barticks around them:
df$`myvariable[1]`
I want to use those variables within a for-loop, and hence, want to change the number within the brackets automatically. Does anyone know how to do this?
PS: This question is different from other questions insofar as R doesn't see my variables as vector variables but rather as single variables that look the same. Hence, the []-part of my variables is seen as only some kind of string and not as a subsetting operator.
PS2: dput(head(zTT$subjects[, c("myvariable[1]","myvariable[3]","myvariable[4]")],4))
structure(list(\`myvariable[1]\` = c(2, 4, 2, 9), \`myvariable[3]\` = c(1,
1,2, 3), \`myvariable[4]\` = c(2, 4, 2, 7)), .Names = c("myvariable[1]",
"myvariable[3]", "myvariable[4]"), row.names = c(NA, 4L), class = "data.frame")

Answer 1

As akrun has suggested, you can use [[. The code below uses your own data frame to construct the string which corresponds to the list names.
temp <- structure(list(`myvariable[1]` = c(2, 4, 2, 9),
`myvariable[3]` = c(1, 1,2, 3),
`myvariable[4]` = c(2, 4, 2, 7)),
.Names = c("myvariable[1]", "myvariable[3]",
"myvariable[4]"), row.names = c(NA, 4L),
class = "data.frame")
for (i in c(1, 3, 4)) {
myVar <- paste0("myvariable[", i, "]")
print(temp[[myVar]])
}