[wix-users] How to use if..else condition in Wix toolset?

[TMG Test]

Hello Team,

Here is my requirement: if web.config file exists in
D:\default\website\web.config I have to copy some files to
D:\default\website location else copy the same files to C:\inetpub\wwwroot
location.

How to write this condition in .wxs file?

Could you help, please?

Thank You,