mask number

[DEVIMPLOY_Autom]

how can i mask this number and after the first four numbers have a dash and before the final three have a dash too, there are 18 characters, is this a pattern?

[Marc_Dillon]

There's no way in Appsheet to mask or force such a format during a user's input, but you can manipulate the inputted text into the appropriate format, and mask it, in another column.

In another column, mask the first 4 characters like this:

"****" & RIGHT( [no reds] , LEN([no reds])-4 )

For the dash, write an IF expression to first determine if the dash exists or not, if not, add it in by concatenating LEFT([no red], LEN( [no reds] )-3 ) & "-" & RIGHT( [no reds] , 3 )