Counters within a template?

[Trana]

Is there any way to put a global variable into a template (like postbit or threadbit) so that I can modify the output with conditionals once criteria is met?

For example, a simple counter count++ placed in a template so that it increases every time the template is loaded on a page, and if the count gets to a certain number I can make a change to the output with an <if>?

I don't know if this can be done in a template without using a plugin or file change.

Thanks!