Hi karthikR,
I doubt that transferring a MIF file via RS232 is the way to go.
The structure of a simple BMP file is very straightforward and well-documented, so if I were you I'd consider sending the bitmap file itself down your serial link. Start by opening your bitmap in a text editor with hex mode and look for the various structures starting with BITMAPFILEHEADER. If you're only going to be dealing with bitmaps of a fixed size and colour depth you should soon be able to see how you can cut to the chase and extract just the array of RGB data you need.
If memory space is an issue, palette based bitmaps are efficient and still pretty simple.
Cheers
Sharkybaba