How can I prepopulate a field in my form?

Not sure if I phrased my question correctly, but please allow me to explain.

I'm making a donation form. So I created a Donation page on my website where a donor can choose what program it wants to donate to by clicking on the button. When donor clicks on the button, it takes him to the jotform.   The problem is, I would need to create a jotform for each program that a donor wants to donate to. I don't want to do that.  Is it possible to, say, create a hidden dropdown selection in the jotform which lists the programs of choice. When the donor clicks on the particular button on the website, it passes that value to the jotform and fills the hidden dropdown with the value. Based on that hidden value, I can then slightly taylor the form for this program.  

I think you can use prepopulated fields in your form to achieve this, please check the following app: http://prepopulate.jotform.io/

This app will help you to generate the URL that you need to use to prepopulate your form's dropdown.

Please check the following links:

http://form.jotformpro.com/form/43446735871968?selectedProgram=Program%201
http://form.jotformpro.com/form/43446735871968?selectedProgram=Program%202
http://form.jotformpro.com/form/43446735871968?selectedProgram=Program%203

You'll notice that depending on the link you click the selected program in the dropdown changes.

Hope this helps.
Let us know if you need further assistance.

Best Regards.