I’ve found your product on Download.com and I’m testing it now. I would like to create a new font based on a font called Humans521 BT. Capital letters would be in Humans521 BT 9 points. I would replace the small letters in the current font by capital letters and whenever a small letter is typed by the user (“a”, “b”, “c”, etc.), I would like to get Humans521 BT 6 points.
This is for a Web application we are using to create online stationery and it’s not possible to change the size of the characters as you type.
The first problem you have is that Humanist 521BT is a commercial, copyright font, so you would have to ask Bitstream Corporation for permission to edit their font. I doubt if they would give it.
So, look for a GNU license font with similar appearance, that you can edit. Bitstream Vera is not quite what you want, but it does have the right kind of license conditions. My own font Verajja is derived from Bitstream Vera.
The next bit is easy. Copy the Capitals to the lowercase, and use the Small Capitals Transformation (Tools, Glyph Transform Wizard) to resize the glyphs and make them slightly bolder.
Font, Test to preview the result. The following screen shot is of Verajja Regular in the Font Test window after using a Small Capitals transformation of 63% and a bold of 12 funits in both x and y directions. It took less than a minute to do. Some refinements may be needed after using glyph transformations to get the weight right.