I need a solution for the example below please,

A1 could hold value 9.5, 7.5 or 0
If A1 =9.5 then I need A2 to show a drop down validation list which is also
at V1.
If A1=7.5 then I need A2 to show a drop down validation list which is also
at V2.
If A1=0 then I need A2 to show a drop down validation list which is also at
V3.

Basically I need to copy an exsisting validation list from V1,2 or 3
depending on the value of A1.

Any help is appriciated.