Nekwaheew is currently the spell that opens the Door to Anywhere. The spell used to be called Yahwahtacsip, the true name of Ledgerdomain but after Charmcaster became the ruler of the realm, the true name was changed.
The spell is not so much a spell but a password, as the Door to Anywhere will open anywhere so long as the user knows the true name of the location.
In Where the Magic Happens, Ultimate Aggregor used Yahwahtacsip to open the Door to Anywhere. The spell is later used by Charmcaster.
In Enemy of My Frenemy, Gwen used Nekwaheew to open the Door to Anywhere.