add controls

I am creating an app that will allow me to enter an unspecified set of
data. Ideally I would like to be able to input the number of desired
sets into a text box and when i click on the command button it opens a
userform with that many sets. A set of data would consist of four
text boxes. I have been able to add controls using controls .add but
I am not sure how to tel vb to do it the specified number of times and
to space them accordingly. The other option I thought of would be to
start with maybe 5 sets and have a button that would add an additional
set as needed. This would involve adding a set of text boxes below
the ones that already exist. I have searched and searched and the
only solution i could find would be to create all the controls and
make them visible or not. This seems like a time consuming process and
would increase the size of the file. If this is the way it must be
done how can i setup 100 sets (400 textboxes total) without doing
each one individually. ANy input or suggestions are welcome. Thanks
for any help i can get.