[TxMt] How to put the cursor at the top of a document

[Gary Ash]

Hello,
I’m working on textmate 2 command that will process data from a file and insert some some information into the activate textmate document
I’ve got the bulk of the job working pretty well except I’d like to ensure the data is allows added to the top of the file. Can anyone tell me how to ensure the cursor is at the top of the document before I insert my data?

Thanks for any help
Gary