Blind Transfer & Meetme Info request

Asterisk 1.8 FreePBX 2.10
I want to:-
Have a Meetme conference eg. 2000
To set that conference up with an extension acting as the admin.
Incoming calls to the DID for 2000 (all works)

Any extension dials out (over external SIP Trunk to PSTN) to external party.
Once call established; blind transfer to 2000; ##2000# (last # speeds it up)
repeat external calls as required

External call hangs up and their line is dropped

Has anyone tried this and got it to work.
For us the last stage put does nothing unless admin extn hangs up and externals are left in Music_on_Hold.