Nintex Forms: image control URL based on uploaded MySite image of current user

Hi there!

I am struggling with the image control in Nintex Forms.

I have an image control and would like the URL to be the uploaded MySite image of the current user.

https://[site]/User%20Photos/Profile%20Pictures/[firstname]_[lastname]_LThumb.jpg

So when a user opens the form, he will see his MySite picture.

Unfortunately, the image control does not allow form variables, named controls or the runtime function UserProfileLookup.

Using a button of the type image won't work either.

How do I manage to do that?

Thank you!