It's not hard to add them all to a control array:
  • Select one of the TextBoxes (the "first" one, if you care about the order of their indexes)
  • Give it a more generic name that is appropriate for all the textboxes (like instead of txtFirstName, make it txtCustInfo)
  • Copy that name from the Property window
  • With the Name property for the TextBox control still highlighted in the Property window, select the next TextBox and Paste (Ctrl+V)
  • Say "Yes" to the "do you want to make a control array" dialog (only happens once)
  • Then just continue with the rest of the textboxes, selecting a textbox and pasting.
Should take less than a minute for 100 controls (depending on how long it takes you to Left Click, Ctrl+V)

The more painful part would be if you have more specific code written already for data validation that references the TextBoxes by name (instead of index). This would require module level text replacement (Replace all instances of txtFirstName with txtCustInfo(0), for each TextBox).