close a binary file !!easy question!!-

i am useing visual basic and i want to know if there is a way to end a binary file at a certain point. ex. i write a binary file with one byte at position 1,000,000 so i now have a file that is 1 million bytes long. how can i just say okay, i just want positions 1-5,000 without haveing to create a temporary file. i am doing these operations on files over 20 GB large so copying is out of the question when all i need to do is remove a few bytes from the end of the file. can anyone help me. is there maybe a library that has this function that i can use. thanx in advance.. i am useing vb 6 ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Deliverables must be in ready-to-run condition, as follows (depending on the nature of the deliverables): a) For web sites or other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. b) For all others including desktop software or software the buyer intends to distribute: A software installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform vb