How would I begin to code a calendar to fill a specific text box instead of the box the cursor is currently in???

What code are you currently using to enter the chosen date into the textbox that has focus.....?

Hi,
depends...do you want to utilize a build in active x control or do you want a more flexible custom approach?
If you use the build in calendar control then you can utilize its click event which will let you assign the value to whatever control you want e.g.:

Private Sub ocxCalendar_Click()

Me.YourControl = Me.ocxCalendar

End Sub

If you want a custom approach then search through the code archive for many many samples. You would just need to modify then to assign the value to wherever you want.
HTH
Good luck