This is not possible with an HTTP redirect, but you can change your link to use:
<a href="mylink" target="_blank"> blah </a>
That will open a new window when the link is clicked. If you need to perform some action when that happens, need to open the window to the new URL, and have that window perform the action instead of the link.
Do you play Magic?
Get TopDecked MTG, the #1 Magic App, built by players, for players. Free to use, forever.