Can the Membership plugin do this?

I'm not using the Membership and Marketplace plugins in the normal way.

The client is a wholesaler and wants to sell only to pre-approved vendors so these vendors have to first contact the client (via phone or contact form), the client approves the vendor and creates for the vendor a userid and password.

Only then can the vendor go to the site to login and order.

I'm having trouble finding out how/where the vendor can login.

The Registration page shows anyone can register and login, so that doesn't work. I tried using the wp-login link but that takes the user into the site dashboard, but not to the website where the items for sale are. As a vendor, I'd be very confused if I were taken into this dashboard and not on the site itself.

Basically, I'm trying to figure out if I'm trying to do something that is not 'meant to be' in the Membership and Marketplace plugins.

What I'm doing is so opposite the normal way of having an open store: I only want to give access to the store to pre-approved vendors who are the only ones who can see the store and order.

I'm getting confused on how to make this work and it may be because it can't work with these plugins. Before I go further, could you let me know if what I'm trying to do will work or not the way I need it to within WordPress?

Thanks for your help and advice.