Hi JoshSWR

Is the CE Marking tab running a custom page?

The Task Launcher uses the following URL format: http://localhost:port/Tasklauncher/PluginName/Target.Action?par1=val1&parX=valY

Sorry, it's actually the 'Sage 200 Accounts Forms' tab. I'm not 100% sure as I didn't set it up, but I would assume so. Are you able to point me in the direction of checking?

Yes it looks like the screen from the Account Forms tab and form launchers.
It's just that the CE Marking tab is highlighted and you mentioned your BP set it up, so thought they may have custom coded a new screen.

If you go into the admin area
Administration -> Customisation -> Company and select Tabs

Have you asked your Sage 200 partner to assist with your request?

Sean

Just checked and that page is using the 'customdotnetdll' action. 

I have asked my sage 200 partner but since its development and not support they want to charge us, and for the feature I want to add it's not worth the money so I wanted to see for myself how it's done. 

Thanks for your help - with the information you gave me I was able to figure out the rest and achieve what I was aiming for

Good news joshSWR, glad I could point you in the right direction. 

Are you able to provide any more information about how data is passed through the task launcher? I've created a button to launch the 'Online Sales Receipt' form in Sage 200, but when launching with the link it doesn't grey out the bank account field like it does if opened within Sage 200, which means the user could change it. My assumption is that this is happening because no value is being passed to the form from task launcher?

Launched with task launcher:

Launched in Sage 200: