Hi @user8283 and welcome aboard 
Glad to tell you that there is a way to open forms from a custom button and we’ve got it covered it in our article - Form widgets: How to open forms from a custom button
Check it out and let me know if it worked for you 
In case I misunderstood you, and it’s not what you are looking for, please elaborate on your use case. I’ll be happy to check things!