[Zope] including a dtml method through a variable

[Declan Shanaghy]

With reference to the usual dtml-var to include a dtml-method in
another page. i.e.

<dtml-var page_dtml_widget>

How is it possible to do this dynamically?
Lets say in some pyhton script i execute a line like this:

if a:
  REQUEST.set("widget", "page_dtml_widget1")
else:
  REQUEST.set("widget", "page_dtml_widget2")

Later on in the dtml method, how can i use that variable for a dynamic
include?

<dtml-var widget>...
...Obviously doesnt work, it just prints out the value of the variable.
After much head scratching i still cant get around this.
Any suggestions anyone?