Your counter file has no flocking and is subject to race conditions. It will be subject to clearing itself or missing counts. Super Search for hit counters to see recommendations from merlyn (I think he has a column on it ;-) and others.

You output perl data to a web page by printing it to STDOUT. It doesn't matter whether the data is text or numbers, just print it where you want it, with the tags you want, or from a template.