Automate Copy and Paste based on Filter?

I very much doubt this is possible, but having seen the quality of advice that is available here, I thought if anybody would know if it's possible it's you guys.

Don't worry Bob, I'm not going to cross-post again - I've learnt from that mistake!

So here's my quandary - I currently have a spreadsheet that has an input screen a formulas page and an output screen.

There's literally thousands of formulas that determine what the output should be, and a list of about 300 items that may or may not have a positive value in the 'quantity' box based upon the input.

I then have a macro that auto-filters the list of 300 items and only displays anything with a value in the quantity box or 1 or greater.

At this point I currently copy the list and paste it into a 4th sheet - which is essentially a letter with room to paste the item list in.

By default the 4th sheet has a 20 row grid to allow for input, however if there are more than 20 items listed on the output sheet then additional rows need to be inserted.

I've put a formula on the 4th sheet that evaluates how many lines are on the filtered output sheet and instructs the user how many additional lines are require and then I have added buttons to insert 1, 5 and 10 additional rows into the grid to make things a little easier.

The trouble is, even this simple procedure is too much for the users to do without messing it up - so I was wondering - is there a way to automate it so that it will evaluate how many rows are required and then insert that many rows - then copy the filtered output list and paste it into the grid on sheet 4.

I hope that makes sense - if you require any additional information please let me know.

Thanks in advance.