frequency domain to time domain with magnitude and phase
Okay, I don't use MATLAB, but I think this Python example represents what you may be asking.

import numpy as np

A = 3 + 4j
k = 5
N = 128

Z = np.zeros(N, dtype='complex')
Z[k]   = A
Z[N-k] = np.conj( A )

z = np.fft.ifft(Z)

print( z )

This will generate a real valued pure tone (all the imaginary values are zero to the limit of precision) signal with 5 cycles in the frame.  The &quot;mirroring&quot; means that for a real signal the DFT is a conjugate mirror image, i.e. $Z[k] = Z^*[N-k]$.  It is common convention to use X, but I like Z too.