May not be doable in a Macro?

Hello all, I need to achieve the following and I am not sure if it is possible... If I roll Xd6 I need the macro to add up the result as follows: 1 = -1, 2 to 5 = 1 and 6 = 2. E.g.. If I rolled 4d6 and the result was a 6, 3, 2, 1 that would equal 3. So 2+1+1+-1 = 3. Is this possible with a macro?  If so any help would be greatly apricated. Thanks in advance. 

What you are describing is a custom d6 which is what a rollable table is perfectly set up to do :) With 3 entries in your table called something like customd6: 1 (weight 4) 2 (weight 1) -1 (weight 1) Then you can roll it with [[ x t[customd6] ]]

Brillant.....It is funny how you can't see things until someone points. Ziechael you are a legend.