anon469793,
To find the period in the middle of a reference and change it to a colon I use the following in the Paratext Find/Replace.
Find:
regex:(?<=\d).(?=\d)
Replace:
:
This says, “use regex” to look for a period that is proceeded by a digit and followed by a digit and replace it with a colon.
Obviously if you have other places in the text where you have digit period digit and want to keep them you would need to expand the find. You might want to do a find first and examine the results to see if there are any items that need to be maintained (like $200.00)