First let me share a little bit about how I use RTM, then ask you for help:

I'm using a personal variation of GTD method with RTM and (allmost) all my tasks need to be entered with three tags:
- client (for who am i going to perform the task. ie: if it is a task within a work project the tag will look like this "c.clientecompanyname". If the task is something like "Clean up car", client wil be "c.me"); this tag allows me to quickly see all tasks awaiting for a specific client by using smartsearch).
- project (this tag helps me see all tags associated to one specific project and they will look somethinglike "p.projectname". Some tasks don't really belong to any project, they are just single action so I tag them with p.single)
- context (finally context helps me know what to do when in a certain context- context can be a place, a tool or a person I have to be with in order to perform the task. Exemples of context tags I use are "x.online"; "x.bussinespartner", "x.phone" etc. (I have some tasks with more than one context tag, for example I can have something I nedd to discuss with my businesspartner and that task can then have both the tag x.phone and x.businesspartner, so say I'm on the train and decide to make somephonecalls I search all tasks with x.phone and that task will show up, but if I happen to meet my business partner I can quickly search "x.businesspartner" ans get all the tasks I need to discuss with him.

(As you've noticed I use the prefix c. for allclient tags, p. for project tags and x. for context)

Now I basically use smartadd a lot to send tasks via e-mail to RTM. And I'm afraid that occasionally I might forget to add one of the three tags above (that is the downside of my method, quite a lot of tagging going on and if you misstag, tasks can fall under the radar). Does anyone know if it is possible to do wildcard search in RTM for something like "NOT tag:c.*" that would show me all tasks without a tag beggining with c.?
(I've tried using the asterisk as a wild card and it doesn't work)

This would be really usefull since I could create a smartlist to add all tasks with a missing tag, and in that way I could easily catch mistagged items and set them straight.

Thanks in advance for any help.