linking to powerpoint file within network

i built an intranet for my company and am having issues accessing files within the WAN but at a different branch. We store our training videos at each branch so there is no delay if we were to drag each file from the main branch. I have shared the C: drive at one branch and created a folder named “training” within the C:. Within there, i have a powerpoint file that i would like to link to the intranet. What kind of link or format would i use to link and open this file from any computer within the WAN?

//computername/C/training/powerpoint.ppt