Create A Text Box That Will Accept Numbers In The Currency Format?

I need to create a control for input a currecncies to a field. I'm planning to use a Textbox.

This is the format of the text box for currencies:

"XXXXXXXX.XX"

the dot "." must be fixed in the textbox and it should be loaded with the textbox. Furthermroe i have plans to code eachtime a user enters a number it should print the numbers from Right ot left.

eg: When user enters Number 1234.34

When the user enter these number they should display them as:

when user enters 1

0000.01

when the user enters 2:

0000.12

when the user enter 3:0001.23

When the user enters 4:

0012.34

When the user enters 3:0123.43

When the user enters 4:(after entering all digits in the number)1234.34

Could any one give a couple of ideas how to creat these kind of boxes?

I was thinking about creating a custom control (a Textbox) but still i need to have a the above format in the textbox!