What are some of the lines in the line and what (how) were they read into? Just "$ENV{VARIABLE}/my/path" or the like ($ENV{VARIABLE}."/my/path" or sprintf "%s/my/path", $ENV{VARIABLE}) isn't working for you?

Update: Ah -- as i look as hardburn's response below, now it makes sense to me that a sample line was '$ENV{VARIABLE}/my/path' ... so, yeah, eval can work, but can also be very bad, as this thread recently discussed