I have had the code for this for years as I have had to do a lot of work in the past on C/C++ header file, a fast and reliable way to convert C format "0x" style hex to assembler trailing "h" style notation. *I would post the code if it was written in 32 bit MASM but is written in MASM style PB so it would be of no use to you.
It has an optional style command line, you can either pass just the source file name to it and it will overwrite the source file OR you can use a second file name if you wish to preserve the source file.