I'm assuming that you need to end up with a text file for upload - here are two things that will make your job easier:
1. Become familiar with the len and left functions. For instance, if the FirstName in the text file needs to be 30 characters, then the formula would be:
firstnamefield + space(30-len(firstnamefield))
2. The space function can be used on its own - if you have a field in the text file that needs to be 30 spaces, then you go with:
space(30)
Depending on how many fields you have to fill, you can just create one formula and tack the elements together with a + sign:
firstnamefield + space(30-len(firstnamefield)) +
firstnamefield + space(30-len(firstnamefield)) +
address1field + space(50-len(address1field)) +
space(50) +
cityfield + space(25-len(cityfield))
etc. etc.
You'll also need to understand the various flavors of the totext function for when you're including numeric values
totext(zip) gives '74,114.00'
totext(zip,"#") gives '74114'
totext(zip),0) gives '74,114'
This can be very tedious - don't try to do it all at once. Get the first element right, then add the second, etc.