I need to replace all : (colon) with :  (colon space). I am able to do this with replace function. 
description_string = Replace(currentSheet.Cells(i, j), ":", ": ")
but this replace time formats (eg 16:20) also. I need to identify the colons : which has number as a preceding value (eg. 9:)
i have tried using regular expressions
[a-zA-Z]:[a-zA-Z0-9] 
as the pattern. The issue is how will I replace only colon from this. If I try replacing, the entire characters before and after the colon is getting replaced.
I tried find and replace but the issue is for the string like
abcd Date:01/01/17 10:18 Des:xyz
all the colons are getting changed to :
The output I want is
abcd Date: 01/01/17 10:18 Des: xyz
 
    