Copy from provided text to a field on the screen--don't use this with VT100 sessions (only send keystrokes with the SendKey function). Note that this does NOT clear any remaining data in the field.
Data String: text to copy to the field
Data Length: ignored unless the STRLEN session option is active
PS Position: position of any portion of the target field, including the attribute.
Returns
Data Length: may be less than data string length, if an attribute byte is encountered during the copy
RetCode: WHLLINHIBITED: unformatted display (no fields present), WHLLPOSITIONERROR: PS position off of the screen, WHLLTRUNCATED: attribute byte hit while still writing
