When I started to make beats about a year ago, I didn't have a midi controller with a modwheel, so I'd have to rely on automation clips to change up things in a song. Now automation clips has it's own advantages. As well as the modwheel. One of the things that stands out of a modwheel is the fact that it's like a humanized automation clip. It gives you more expression as a producer.

So I've come up with this technique that would mimic a modwheel.

Step 1: Make sure you have some kind of controller in your project, whether it's an automation clip, fruity formula controller, peak controller, etc.

Step 2: Right click on the parameter that you want to automate, and click on "Link to Controller".

Step 3: Now if you had done step 1 corrrectly then you should see a something that says "Record On Automation" under internal controllers, click it and make sure it's checked.

Step 4: Now go to a new empty pattern clip and place it wherever you want to start automating

Step 5. I recommend you turn on the tempo counter thingy and click record (record to Automation & Clip). Move the parameter like you would usually do to edit it while recording.

Step 6. Once you're done recording and everything goes well, you should now see a pattern that kind of looks like an automation clip.

Step 7. Now you have the choice to do whatever you want with your new "humanized" automation clip, you can paste any part of your song, you can edit it even more by going in te pattern clip. You can even go crazy and change it to an actually automation clip by going to the edit menu and clicking "Turn to Automation". Once it's an automation clip you can go even crazier and scale the levels, deform the shape and even analyze an audio file which is REALLY COOL.

Now obviously since it's Fl Studio, there's more than one way to do the same thing. So you can do the exact same thing using an xy controller or a Fruity Formula Controller or something I haven't touched yet
Anyway have fun and good luck, if you have any problems I'd be glad to help even further.