How to create a property checkpoint for hard code value & a variable

the string you want to use as a baseline will look something like this:

"Last Visit " + aqDateTime.Today() + " (" + myvariablefornumberofdays + " days ago)"

Instead of using a Property Checkpoint, build your own with an If Then.  See attached screenshot.

What Marsha_R said, but with two notes:

1) You may need to format the date using aqConvert.DateTimeToStr or aqConvert.DateTimeToFormatStr.

2) No need for If...Then -- you can use variables in checkpoints directly. First, create a checkpoint with the hard-coded value first. Then click the checkpoint's Value string, press F2 and replace the hard-coded value with a variable.