[Urgent] Dynamic DropDown based on Accounts' module field "Type of Partner"

Hi All,
I need to create, automatically, a DropDown list filtering the content of the Accounts module.

I.E. I have a field that may contain:

  1. End User
  2. Integrator Partner
  3. Commercial Partner

than, I need to create a DrowpDown for only Commercial Partner selected in the “Accounts” list.

Please let me know if someone alredy did that or if there’s any kind of solution.

Looking forward to read from you asap.