I'm able to put together the form and command buttons, etc., but cannot
figure out the way to have the numbers in the form go to specific cells on
the active worksheet.

If you don't mind the contents of the cells appearing in the TextBoxes
when the UserForm is shown, you can use the TextBox's ControlSource
property, e.g. Sheet1!A1. Or you can put code behind the "accept"
CommandButton, e.g.:
Sheets("Sheet1").Range("A1") = TextBox1.Text 'or
Sheets("Sheet1").Range("A1") = TextBox1.Text 'or
ActiveSheet.Range("A1") = TextBox1 'or
ActiveSheet.Range("A1") = TextBox1.Text

HTH,
Merjet