unable to select the date value for column type 'cal'

Using DHTMLXgrid we have created the date field, it is picking the date value properly, but the problem is when we need to select the date to copy and paste it in another date field, we are unable to select the date value(for column type ‘cal’), Please suggest us any possible solution.

Could you please, provide with a complete demo including your custom column type, where the described problem, can be reconstructed locally.
Here you can find a tutorial about creating a complete demo:
docs.dhtmlx.com/tutorials__auxil … pport.html