How do I merge specified cells

[StringAech]

hey guys!
i want merge some specified cells just like colspan="2" in HTML, but there only can merge the all columns by use col_merge().
what should i do ?
for example:
i want this table:

Layer 1	Layer 2	Layer 3
Layer 4	Layer 5	Layer 6

to change like this

Layer 1	Layer 2	Layer 3
Layer 4		Layer 5

or

Layer 1	Layer 2	Layer 3
	Layer 5	Layer 6

[ixodid198]

I too have this problem. I posted on Stackoverflow and @MarBlo posted a possible solution. However, I like simplicity so I went with flextable.

[StringAech]

Thank you very much for your answer!
flextablecan help me a lot.