Can't use combination of parentheses and variables in scripts

I have problems with replacing parentheses in combination with variables, in ssh. For instance, replacing (hello123blablabla) with (hello). So, it replaces all together, and parentheses as well, at least that's what I expect. But the variable value is lost when using the parentheses:

$ hellovar=hello
$ perl -pi.bak -e 's/\(hello[1..3].*?\)/($hellovar)/g' file.txt

The command is printed as following

$ echo perl -pi.bak -e 's/\(hello[1..3].*?\)/($hellovar)/g' file.txt
perl -pi.bak -e s/\(hello[1..3].*?\)/($hellovar)/g file.txt

But I need it to be translated as follows:

perl -pi.bak -e s/\(hello[1..3].*?\)/(hello)/g file.txt