Use a open polyline to split a closed polyline into two creating a space between then utilizing user input

[igorDBF96]

Hi!

I want to create a code (using c#) that turns a closed polyline like this:

Into this:

Using an open polyline as a reference (the space between the two closed polylines would come from a value the user would provide).

Does anyone have any tips that could help? I'd appreciate any help you can provide.