The whole point of the ASSIGN function (you can key it into the edit window and hit tab, and it will default to an F1 or similar identification) is to utilize automatically retrieved data within your routine and do something with that data... automatically when the routine executes. It does not need any user involvement during execution. You add it into the program and properly reference the data to produce the intended result..
NEWANGLE would be the new feature ID of the assign function you type in.
DIMANGLE1 would be the feature ID of your first plane's angle, to axis line
DIMANGLE2 would be the feature ID of your second plane's angle, to axis line
My methodology and your methodology you describe are very diverse. What I suggested locally and immediately adjusts the machine coords into part coords, as soon as the part coords are defined. This method aids in producing REPEATABLE results, which your routine, as described, is not attaining.
