Spreading percent based upon criteria

Hi all, I've been trying to figure out how to do this for the past couple of hours.

Basically, I want to spread out a percent (lowest being 4% and highest being 10%) based upon cost-of-living (COL) criteria. I've reindexed it so I already have the column set up where the 4% would go to the lowest COL (0.5% in this case, since am not assigning the percent to any of the negative values shown in the '3rd Step' column) and 10% would go to the highest COL of 51.8%. All the values between .5% and 51.8% would fall in between being assigned 4% to 10% cost-of-living funds.

How would I go about setting this up? I have no clue where to begin. I'm attaching the file to show you what I'm talking about.

Thanks very much in advance for your help!

Please see attached. The first column is based on the total number of cells above 0% (cell 0 = 4% and cell 120 = 10%), and the second column is based on the percentages in column H (0% = 4% and 51.8% = 10%). I'm not sure which one you would prefer.