...and it always wants to edit the existing record that I am viewing instead of going to the related record that i selected from the dropdown.
Related in what way, by what fields?
Use a different field formatted with your drop down. You may want to specify global storage for it.
Option 1: Define a new relationship that matches to this global field. Now you can specify data in the global field and the relationshp will match to the value selected. A portal can list the matching records or Go To Related Record can pull them up in a found set.
Option 2: Use global storage on this newly added field and use a script to perform a find to pull up a found set of records.
See this thread for examples of how global fields can be used in scripts that perform a find: Scripted Find Examples