Fairly straight forward... for new keywords and small adgroups.
However, I'm looking for a way to automate this process for a large number of _existing_ campaigns/adgroups/keywords.
This seems possible through Adwords API... I'm looking for a good tool or a way (other than 'write your own Adwords API app') that is capable of tying into an Adwords account and batch-process this, so that I don't have to do it manually.
Actually ended up accomplishing this using Adwords Explorer and good ol' Excel by exporting the campaigns and adding the dynamic variables to the URLs with search and replace in Excel. Then just import it back into Adwords Editor and post changes to the Adwords account.. Not the greatest solution, but it worked :p