Chopping Off The First Letter Of A String

Basically i have a string with a value that either starts with U or N.

If the string starts with a U, I would like to chop that U off but leave the rest of the string. If it starts with an N, then i would need to keep the N on the string. For example,

strUID = U369373

If strUID = 'starts with a U' Then
'Chop off the U to create 369373 instead of U369373'
End If

Should be a fairly easy logical statement, but i just forgot the variables to do that.