I am here to give u question. that is beyond exception but i think somebody will have answer for this.
Question: Once user clicks an anchor tag
You cannot, from a given web-page, specify in which software a link should be opened.
At best, if your anchor points to a specific kind of file (like a .doc), the system will know that it must use some other software than the browser (like MS Word -- or ask the user which software he wants to use). But, for an HTML page, the browser will be used.
And your website has no control over this.