Getting variable from asp/aspx to workflow

I need to move a variable saved on a SP list item(LIST A) to a workflow that starts on the creation of a new item in a different list(LIST B). This new item on LIST B will be created upon pressing an .aspx button in a web part on LIST A's edit item form. When clicked, this button will call a C# method taking a value (call it School_ID) from the item on LIST A. C# code will then create a new item on LIST B and fill it with the value retrieved from LIST A. the School_ID.

This workflow can then, using the school_ID value retrieve further information from the item on LIST A which it now has a (unique) Identifier as a reference.

My question is, Is this at all viable. Is there a better way to achieve this?