Create a new Site Column in one of your Site Collections.
Add this column to a list or library and add at least one item to the list with data in the new column.
Wait for, or force, a search crawl.
In the SharePoint search admin site find Manage Search Schema.
In the Schema page click Managed Properties, if not selected.
Search for “Int” and select a property that does not currently have an assigned Crawled Property.
Edit the property and add an Alias. "MyInt"... what your user will type in a search.
Just below Alias, click Add a Mapping and select the Crawled Property for your new Site Column. (If your column is named "Item Count" then the Crawled Property would have a name something like "ows_Item_x0020_Count". (guessing from memory!)
Request a recrawl of the library that contains these documents. (Library Settings, Advanced)