Removing Existing Loads, Applying the Element Pressures using OpenSTAAD

I am struggling to apply the element pressures using the OpenSTAAD. Can someone help me to sort this out. Following are the tasks I am trying to do:

1. Verify if a 'Reference Load' with the specified load index (e.g., R74) exists in the selected STAAD File.

a. If exists, remove all existing loads (which I am NOT clear how to do) and set the load active (I can do it using the available procedures)

b. If doesn't exists, create one with the specified load case number, type and title (This I can do using the available procedures)

2. Once, the reference load is set active,

a. How to apply the element pressures for a range of plates (I have an array for the same) in the following format:

Plate No., PrDirection, Pressure.NodeA, Pressure.NodeB, Pressure.NodeC, Pressure.NodeD