Hardcode Sales Employee in BP search

Hello Experts,

I need help in order to ensure that sales employees have access to only Business Partners that contain their SlpCode. What I would like is the following:

User Opens Sales Order form

User clicks into CardCode textbox and hits tab

SAP displays only BP's for whom the assigned sales employee is the user logged in (instead of displayting list of all BP's)

Is there a way to permanently 'hardcode' a filter on the list of BP's to show only the current user's Business Partners?