Blind transfer as default on VVX 310

Hello

I am hoping someone can help me with a small issue I am trying to resolve.

I bought 250 Polycom VVX 310 phones for a voip deployment here in our offices.  I am trying to find how I can set the blind transfer as the default on these phones - can't seem to find it anywhere so users have been doing this on a per-call basis.

Thank you in advance for your help

Franco Clarizio