Change ruler units to pixels
Change paper size to a specific value in pixel
Create the the letter, one by one in each page
Select all objects and weld to make just one object them
Export the page letter
Select True Type Font file type
Type Font Name
Change Grid Size to fit the page size you defined
Change Space width, to set space between letters
Select the letter you want to save into the font file
Change Design size to fit the page size
Define Baseline, to set space between bottom and the letter
To complete the font file, you have to export each page you created
