how to capture specific value from a field to my application textbox

See more:

ASP.NET

WinForms

Hi,
my requirement is to capture value from a billing software and use the value as an input to my application.

i have my application ready but don't know how to capture the value of specific field of some unknown application.

i am able to capture the screenshot and save in image format but dont know how to capture data from that screenshot,so that i can use the data in my application

THE MAIN TASK IS HOW TO CAPTURE THE SPECIFIC FIELD FROM THAT IMAGE AND USE IT IN MY APPLICATION

if you can tell me the approach i will be very thankful to you.

plz tell me the step by step approach.

some usefull link also you can share