The URL to a task should be included in the export CSV file.
this has been suggested in 2018 but in ‘use cases’ > Including the Task Url in Export
this feature would really make my life easier!
Please vote up!
I disagree, the URL to a task is really easy to create with the gid, so you can create your own column if you need it. A CSV is about providing the basic building blocks, and then you do the work to build what you need with it 
When you import the CSV, the taskId is a number instead of text so that the task id in Excel is wrong… Not easy solution and a lot of manual process that is crap!
For reference:
Which I believe is something Asana can’t do anything about, a CSV doesn’t carry anything about the format, it is as raw as it can be.
I agree I have to keep everyone accountable for their work and a lot of folks do not even live in asana like I do as the project manager. So exporting an excel or csv file of an assignees tasks with a link to the task can actually help us get things done and hold folks accountable fast.
Note: Not a solution but marked as such to elevate a key reply
Asana2Go (disclaimer: I’m the creator) has an easy way to create a CSV that includes the task URL automatically (choose CSV - Detailed). With Asana2Go, there’s a way to get those CSV row into either Excel or GSheets without even creating a file! See the Help link in the main Asana2Go window.
But there are around 20 other outputs (lists, tables, etc.) that may be more appropriate for your purpose, @Katie_Dix.
Thanks,
Larry