I am creating an affiliates-only site for an affiliate marketing program, in order to share marketing materials and links not available to them in the regular panel they use to check their stats. I can create each username from my list of affiliates to match their affiliate ID in their account - for example "1489820" - and when they login to my WordPress site I want the links they see to show their own ID in the right place so they can grab their links and use them from the marketing pages I will create.
A typical link (where the XXXXX needs to be replaced with their username) would be:
so I need the this link to show to username 1489820 as:
Can someone point me in the right direction?