develop multitap keypad code

Dear all,

I am working on a project which requires multitap keypad similar to which we use in the mobile phones.I am writing the back end code for the keypad,I have been successfull till the point to produce multitap functionality(eg:button2 include A,B,C,2) but when i write it to the text box using Ptsetresource complete string in the text box is being replaced instead of the particular character .
I have been looking for a method to move cursor by one step right after using the ptsetresource ,but i am unable to find one.
If anyone have idea how to chieve it please share.

Thanks and regards
Pradeep … ytext.html