Alternate UI to RPG

We have built a web portal to allow web integration for external clients
and this is using php with xmlservice and it is working very nicely.

Now we want to provide some of the internal functions currently only
available in 5250 green screen.

NOT looking for 3rd party solutions ... No vendors please.

The application is large and we are looking at the 80/20 rule. 20% of the
menu options are accessed 80% of the time.

My question/enquiry is to people that have been down this path - somewhat
regardless of whether they used PHP or nodeJS or Python or ???

Did you modify the existing RPG to enable input from either 5250
Interactive Green Screen AND Web or did you separate the screen logic to
new programs or how did you retain the investment in the existing program
logic.

Would be interested in any comments

Cheers



Don Brown