There's nothing of that sort that we can think of. The only thing you can use is to customize the footer of the Web Interface page. in the footer, you can place a link to your own HTML page with the agreement and all the necessary info. Then, in the confirmation for the Custom Command, you can inform the user that by clicking the button, the user agrees to the terms and conditions, and also you can mention the link at the bottom of the page where the user can read the text of the agreement. That's probably, the only option you can use.
To customize the page footer:
- Start the Web Interface Customization tool.
- In the Interface Type drop-down list, select the Web Interface you want to configure.
- Activate the Miscellaneous tab.
- Click Customize Page Footer.
- In the HTML for page footer field, specify HTML-formatted text that will be displayed in the page footer.