ORDER BY Issue on funky field names

Hello,
I am using FOR XML EXPLICIT

Problem is, I need to sort by [MyColumn!1!MyCol].

This column contains date in string format, And I want it to be sorted as if it was a date.

so I tried this

ORDER BY CONVERT(DATETIME, [MyColumn!1!MyCol])

it gives me error that ORDER BY items must be in select list
The whole query is actually a UNION of 2 queries

Please help me with this

Thanks,Order by has problems with column aliases. So try:
ORDER BY CONVERT(DATETIME, <statement for column value>)
i you have
...
, my_string_date+' '+my_string_time as [MyColumn!1!MyCol]
....

use

ORDER BY CONVERT(DATETIME, my_string_date+' '+my_string_time)