How can I copy a dataframe in R to a new one

I am trying to create a new datframe using paste0 function and i need to copy an existing dataframe into it.
e.g.

ty <-"min" 
If (nrow(paste0("myolddata", ty) >1)
{
Paste0("mynewdata",ty) <- paste0("myolddata", ty)
}

But this paste0 is just returning a string and not able to create/ access a dataframe.

A help on understanding this is much appreciated.

Thanks.