Thanks Patrick for the pointer !
I was almost sure that the HTML modification wont work but just thought if somebody had an alternative way of doing it
I have worked out a work around which may be useful but tedious (till we have new version supporting the requested feature)
Create a participant template for all types of listed calls-In TMS- Bookings- Participant Templates.Create each type of template which are commonly used "for IP" "for IP-H.323" "for ISDN"& "for IP-SIP"
Whenever a VC is scheduled by admin, by default all of the above 3 types can be added to the conference.
The details of dial in details do come up on email invite
Do let me know if this works for you or if there are easier ways of doing it
Cheers !