I actually advocate the use of pressure (g/mm^2) rather than force (g) for PWT for a few reasons: the VF filament increases in diameter at high bending forces, so the bending force is applied over a larger area; VFs use a logarithmic scale of actual force to create a linear scale of perceived intensity; PWT in force is rarely normally distributed so "normal" statistics are not appropriate (t-test, ANOVA, etc) nor is the use of symmetrical SEM on graphs. A great, physiological argument for the use of pressure is shown in figure 8 of this nice study: http://brain.oxfordjournals.org/content/137/3/724
Sorry, I don't have a spreadsheet for the conversion. For the conversion from filaments to pressure, I measured the bending force of each filament on a balance, divided by filament cross sectional area (from manufacturer), and then fit the plot of pressure vs filament number with a line of best fit. I then used that equation to transform all my data in Graphpad from filament number to pressure. I had to recalibrate periodically, and then just created another conversion equation in Graphpad with the updated values. I mostly used filament number in the SUDO paper to make the comparisons between Chaplan and SUDO easier to follow.
But this might also help - I put a link to a spreadsheet in the comments section of the SUDO article, which I think is lost after Mol Pain was picked up by Sage publications. It was meant to help clarify the adjustment factor and give a means to convert old data collected with Chaplan to SUDO to standardize datasets. here is the sheet: http://bit.ly/1MJhnwd