Is is possible to create/use a regular expression pattern in ruby that is based on the value of a variable name?

For instance, we all know we can do the following with Ruby strings:

str = "my string"
str2 = "This is #{str}" # => "This is my string"

I'd like to do the same thing with regular expressions:

var = "Value"
str = "a test Value"
str.gsub( /#{var}/, 'foo' ) # => "a test foo"

Obviously that doesn't work as listed, I only put it there as an example to show what I'd like to do. I need to regexp match based on the value of a variable's content.

ruby regex
Edit
Report