Need to call a number and then dial contact? how to do this?

[Nosey]

I need to be able to dial the same number everytime I make a phone call, then I enter the number I want to call, kind of like using a calling card, when I put in my contacts the way I need to do it for each person ie:

mainnumber(p)2contactnumber ie: 123-456-7890p2123-456-7890

it works, but then I add my 2nd contact person with the same main number but a different contact number, when I save this, it deletes the original contact thinking that it's the same number

is there anyway to do this? I want to be able to hit 1 button to call, not dial the main number and then dial the contact number

thanks in advance

(this is for goggle voice, I dial my number (it goes into voicemail) I then dial "2" contact number "#" and I am connected)